A student performed the following steps to find the solution to the equation x^2-2x-8=0. Where did the student go wrong?

Step 1. Factor the polynomial into (x-4) and (x-2)
Step 2. x-4=0 and x-2=0
Step 3. x=4 and x=3

A. The student did not make any mistakes, the solution is correct
B. in step 1
C. in step 2
D. in step 3

Answers

Answer 1
In step 1, because you want to find factors that multiply to -8 and add to -2. So the correct factorization is (x-4)(x+2). The student got the minus sign wrong.

(Then in step 3 the x=3 is also very wrong, but that looks more like a typo).
(Also, it should be x-4=0 OR x+2=0, there is no x for which both factors are 0 at the same time!)

Related Questions

jill traveled to the ferry office and back. the trip there took 5 hours and the trip back took 4 hours. she averaged 65 mph on the return trip. find the average speed of the trip there

Answers

We know from physics class that the formula for distance of a linear motion is given as:

d = v t

Where,

d = distance travelled

v = average velocity

t = time it took to reach the destination

Since the distance going to the office and back is just similar, therefore we can simply equate the two:

v1 t1 = v2 t2

Where 1 signifies going to the office and 2 signifies going back from the office. Therefore this yields to:

v1 * 5 hours = 65 mph * 4 hours

v1 = 52 mph

 

Answer: The average speed going to the office is 52 mph.

The average speed of Jill's trip to the ferry office was 52 mph, calculated by dividing the distance of 260 miles by the time of 5 hours.

To find the average speed of the trip there, we need to know the distance Jill traveled to the ferry office. Since she averaged 65 mph on the return trip which took 4 hours, the distance is calculated as speed x time, which equals 260 miles (65 mph x 4 hours).

The distance to the ferry office is the same as the distance back, so Jill also traveled 260 miles on the trip there. Given that the trip there took 5 hours, we can find the average speed by dividing the distance by the time. The average speed is 260 miles / 5 hours, which equals 52 mph.

Find the greatest common factor for the group of numbers. 12 ​, 28 ​, 24

Answers

Final answer:

The greatest common factor (GCF) of the numbers 12, 28, and 24 is found by identifying the smallest powers of their common prime factors, which are 2 and 3. Multiplying these together, 2 squared times 3, gives us the GCF of 12.

Explanation:

To find the greatest common factor (GCF) of the numbers 12, 28, and 24, we break each number down into its prime factors:

28 = 2 x 2 x 7

The smallest power of 3 that is common is just 3.

Therefore, the GCF of 12, 28 and 24 is 22 x 3 = 4 x 3 = 12.

14. Find the coordinates of the circumcenter for ∆DEF with coordinates D(1,1) E (7,1) and F(1,5). Show your work.


1.       In triangle ∆PQR, C is the centroid.

 

a.       If CY = 10, find PC and PY

 

b.       If QC = 10, find ZC and ZQ

 

 

c.       If PX = 20, find PQ

Answers

The centroid C divides the length of each median PY, ZQ, and XR into the ratio of 2:1 as shown in the diagram below

a) CY = 10
    PC = 2×10 = 20
    PY = 20+10 = 30

b) QC =10
    ZC = 10÷2 = 5
    ZQ = 10+5 = 15

c) PX = 20
    PQ = 2×20 = 40

what is the sum of 27 and 5 times a number is 187

Answers

27+5x=187
5x=160
x=32
.

(12x 4 + 17x 3 + 8x - 40) ÷ (x + 2)

Answers

(12x^4 + 17x^3 + 8x - 40) ÷ (x + 2)

 =‌12x^4+17x^3+8x−40 / x+2‌ =‌(x+2)(12x^3−7x^2+14x−20) / x+2‌ =12x^3−7x^2+14x−20

What is the point of symmetry for the circle (x – 5)2 + (y + 4)2 = 25?

Answers

In a circle, the point of symmetry is the centerpoint; any straight line that passes through this point is a line of symmetry. The standard form of equation of a circle is given as:

(x – h)^2 + (y – k )^2 = r^2

Where,

h = x coordinate of the center

k = y coordinate of the center

In the problem statement, we are given that the equation of the circle is:

(x – 5)^2 + (y + 4)^2 = 25

So identifying the variables from the standard form of equation of a circle:

h = 5

k = - 4

 

Therefore the point of symmetry is (5, -4).

What is the product of any integer and –1?

Answers

Since negative 1 is negative, we multiply by 1 and make it negative. Therefore, if the integer is x, the product of that and negative 1 is -1*x=-x

GEOMETRY- What is the area of the figure, show your work please!

Answers

Since this is a 45-45-90 right triangle, the hypotenuse = sqrt2 * leg
24 is the hypotenuse so we need to find the leg.
24 = sqrt2 * leg
Divide both sides by sqrt2
leg = 16.97
A = (1/2)b*h
A = (1/2)*16.97*16.97
A = 144ft^2

Which graph represents a reflection of f(x) = 1/10 (10)x across the y-axis?

Answers

This is the concept of transformations, given the function given by f(x)=1/10(10)^x, when the function is reflected along the y-axis the new function will be given by f(x)=1/10(10)^(-x). This will mirror the original function.


Answer:

We have to find a graph which represents a  reflection of f(x) = 1/10 (10)x across the y-axis.

As we know that on reflecting the graph across the y-axis the x-coordinate of the point changes to opposite sign nut with same magnitude and the y-coordinate remains same.

Hence, the function f(x) is transformed to:

[tex]f(x)=\dfrac{1}{10}\times 10^{-x}[/tex]

The graph of the function passes through the point (0,0.1) and is a strictly decreasing function.

and the end behavior of the graph is that:

when x→∞    f(x)→ 0

when x→ -∞    f(x) → ∞

Which of the following statements is false?
A. Opposite sides of a parallelogram are congruent.
B. A rhombus is a regular polygon.
C. The diagonals of a parallelogram bisect each other.
D. A rhombus is a parallelogram.

please explain

Answers

B.
(ignore this text right here because this website doesn't want me to get straight to the point)

if a number is tripled , it equals the product of four and the number diminished by two. find the number

Answers

so basically, translating it to algebra:

3x = 4(x-2)
3x = 4x - 8
flip the like terms to the other sides so they become similar;

8 = 4x -3x
8 = x

And the number is 8!

1. Which of the following statements is true? A. 15 ÷ 0 = 0 B. 15 − 0 = 0 C. 0 ÷ 15 = 0 D. 15 + 0 = 0

Answers

Answer:
The answer is C. 
Answer is C. 0 ÷ 15 = 0

A scale model of a human heart is 198 inches long. The scale is 34 to 1. How many inches long is the actual heart? Round your answer to the nearest whole number.

Answers

 would be 198 / 34 =  5.82  = 6 inches to nearest whole number.

Monica gets on an elevator in a skyscraper. The elevator starts to move at a rate of -20ft/s. After 6 seconds on the elevator, Monica is 350 ft from the ground floor building.

1) The rate of the elevator is negative. What does this mean in the situation? What value in the slope-intercept form of an equation does the rate represent?

2) How many feet was Monica above the ground when she got on the elevator? Show work

3) What value in the slope-intercept form does your answer to part a represent?

Show all work

Answers

1)

negative rate, means is decreasing, rather than increasing, meaning is going to 0 or beyond, instead of going up.

well, the slope is the rate of change of "y" in respect to "x", y = mx + b

2)

well... let's see, the elevator is going down by 20ft/s, so every second is 20feet, now, she was in the elevator for 6seconds, that means 6 * 20, 120feet, however, 6secs later, she's 350 "above" the ground, she's not really on the ground yet.

so, she went on the elevator down for 120feet and was above the ground 350feet, she was up high 120 + 350 feet from the ground.

3)

hmm not sure what's asking
Final answer:

In this scenario involving an elevator's movement, the negative velocity indicates downward motion and corresponds to the slope in the equation of a line. By applying the slope and initial conditions, we calculated that Monica was initially 470 feet above the ground, which is the y-intercept in the slope-intercept form.

Explanation:

The student's question involves understanding the implications of negative velocity in a real-world situation involving an elevator, calculating an initial position based on this velocity and elapsed time, and tying these concepts to algebraic representations in slope-intercept form.

A negative rate of -20ft/s indicates that the elevator is moving downward. This rate represents the slope in the slope-intercept form of an equation, y = mx + b, where m is the rate of change or slope.To find how many feet Monica was above the ground when she got on the elevator, we use the formula y = mx + b, where y is the final position (350 ft), m is the rate of change (-20 ft/s), and x is the elapsed time (6 s). Replacing the values and solving for b (initial position), we get 350 = -20(6) + b, leading to b = 470 ft. Therefore, Monica was 470 feet above the ground when she got on the elevator.The answer to part a, -20ft/s, represents the slope, and the answer to part b, 470 feet, represents the y-intercept (b) in the slope-intercept form.

How many hours is from 9:00am to 6:00 pm?

Answers

9 am to 6 pm is a 9 hour difference. hope this helps

a telephone pole casts a shadow that is 34 m long. find the height of the telephone pole if a statue that is 36cm tall casts a shadow 77cm long

Answers

This is the concept of proportionality, the length of the pole will be given by:
[length of the post]/[length of the shadow]=[length of the statue]/[length of the shadow of statue]
thus;
suppose the length of the pole is x m
thus;
x/34=36/77
x=36/77*34
x=15.8 m
the answer is 15.9 m

Two mechanics worked on a car. the first mechanic worked for 5 hours, and the second mechanic worked for 15 hours. together they charged a total of $1450 . what was the rate charged per hour by each mechanic if the sum of the two rates was $160 per hour

Answers

the first mechanic = a
the second mechanic = b

the first mechanic works for 4 hours = 4 * a
the second mechanic works for 15 hours = 15 * b
total charged = t

t = 4a + 15b

sum of their rates:
a + b = 160
b = 160 - a

t = 4a + 15b
1450 = 4a + 15 * (160 - a)
1450 = 4a + 2400 - 15a

now let's make the formula easier.

15a - 4a = 2400 - 1450
11a = 950

a = 86.36
b = 160 - 86.36 = 73.64

A person died leaving behind inheritance of Rs. 300000. Distribute the amount among 4 sons and 3 daughters so that each son gets double of what a daughter gets. Find the share of each when a debt of Rs. 80,000 was also to be paid.

Answers

s=2d

4s+3d=300000-80000

4s+3d=220000, now using s=2d in this equation you get:

4(2d)+3d=220000

8d+3d=220000

11d=220000

d=20000

So each daughter gets 20000 and each son gets 40000.

The inheritance problem deals with distributing Rs. 300,000 among 4 sons and 3 daughters after a Rs. 80,000 debt is paid. Using algebra and ratios, it is determined that each daughter receives Rs. 20,000 while each son receives Rs. 40,000.

The situation given is that a person dies leaving behind an inheritance of Rs. 300,000, which must be divided among 4 sons and 3 daughters such that each son receives double what each daughter gets. Additionally, a debt of Rs. 80,000 is to be taken out of the inheritance before distribution.

First, we need to consider the debt. Subtracting the debt from the total inheritance, we have:

Total inheritance after debt = Rs. 300,000 - Rs. 80,000 = Rs. 220,000

Now, let's assume each daughter gets x amount. Therefore, each son gets 2x the amount. We can set up the equation accounting for all sons and daughters:

3x (daughters' shares) + 4(2x) (sons' shares) = Rs. 220,000

Simplifying:

3x + 8x = Rs. 220,000

11x = Rs. 220,000

x = Rs. 20,000 (share of each daughter)

Consequently, the share of each son will be double that of a daughter, which is:

2x = 2(Rs. 20,000) = Rs. 40,000 (share of each son)

The distance between the earth and the sun is approximately 93 million miles. what is this number written in proper scientific notation?

Answers

Scientific notation of distance between the earth and the sun is approximately 9.3 x 10^7 miles.

What is Scientific notation ?

Scientific notation is the way to express the large value in short form. The number in scientific notation have two parts. The digits (decimal point will place after first digit) × 10 ( the power which put the decimal point where it should be).

Here it is given that The distance between the earth and the sun is approximately 93 million miles and 1 million miles equals 1,00,000 miles.

Now, writing 93 millions Scientific notation by writing 1,00,000 in power of 10 and 93 as 9.3 x 10 :

93 million miles = 9.3 x 10 x 1,00,000

                          = 9.3 x 10^7

Therefore, Scientific notation of distance between the earth and the sun is approximately 9.3 x 10^7 miles.

Read more about Scientific notation at:

https://brainly.com/question/18073768

#SPJ2

The distance between the Earth and the Sun (93 million miles) in scientific notation is [tex]9.3 *10^7 miles[/tex].

To write the distance between the Earth and the Sun (93 million miles) in scientific notation, follow these steps:

First, write 93 million as a standard numeral: 93,000,000.

Next, identify how many places to move the decimal point to get a number between 1 and 10. For 93,000,000, the decimal point moves 7 places to the left.

After moving the decimal point in 93,000,000.00 by 7 places, you get 9.3, which is between 1 and 10. This is known as mantissa.

Mantissa = 9.3

Write the number as a coefficient multiplied by 10 raised to the number of places the decimal was moved. This is called the exponent term. Exponent term = [tex]10^7[/tex].

Scientific notation of a number = Mantissa*Exponent term

So, 93,000,000 = [tex]9.3 *10^7[/tex].

Therefore, the distance between the Earth and the Sun in proper scientific notation is [tex]9.3 *10^7 miles[/tex].


Solve each system of equations by using elimination.

7)2t-u=17
3t+u=8

8)2j-k=3
3j+k==2

9)3c-2d=2
3c+4d=50

Answers

7. 5t= 25. 3(5)+u=8
t= 5. 15+u=8
u=-7

8. 5j= 5. 3(1)+ k= 2
j=1. k= -1

9. 6c - 4d= 4. 3(6)+4d= 50
3c +4d= 50. 18 + 4d= 50

9c = 54. 4d= 32
d= 8
c = 6

How many reflectional symmetry does a regular hexagon have

Answers

6... I hope this helped

Find the equation of the quadratic function with zeros -1 and 1 and vertex at (0, -4).

Answers

since the vertex is at 0,-4 and the zeros are above it, we'll use a vertical parabola equation, namely with the dependent variable to be the "y".

bear in mind that, a zeor or solution of say -1 and 1, simply means x-intercepts at -1, 0 and 1,0.

[tex]\bf \qquad \textit{parabola vertex form}\\\\ \begin{array}{llll} \boxed{y=a(x-{{ h}})^2+{{ k}}}\\\\ x=a(y-{{ k}})^2+{{ h}} \end{array} \qquad\qquad vertex\ ({{ h}},{{ k}})\\\\ -------------------------------\\\\ vertex\ (0,-4)\ \begin{cases} h=0\\ k=-4 \end{cases}\implies y=a(x-0)^2-4\implies y=ax^2-4 \\\\\\ \textit{we also know that } \begin{cases} y=0\\ x=-1 \end{cases}\implies 0=a(-1-0)^2-4 \\\\\\ 0=a(-1)^2-4\implies \boxed{4=a}\qquad thus\implies \boxed{y=4x^2-4}[/tex]

The value of a $225,000 house increases at a rate of 3.5% each year. Use a graph to predict the value of the house in 8 years.
A) ≈ $276,582
B) ≈ $286,263
C) ≈ $306,652
D) ≈ $296,282

Answers

The growth function is
V (t)=V0 (1+r)^t
V (t) ?
V0 225000
R 0.035
T 8 years

V (8)=225,000×(1+0.035)^(8)
V (8)=296,282

The value of the house in 8 years. (D) ≈ $296,282

How to predict the value?

The given parameters are:

Initial value, a = $225,000

Rate, r = 3.5%

The scenario is an illustration of an exponential growth function.

So, we have:

V(x) = a * (1 + r)^x

Substitute known values

V(x) = 225000 * (1 + 3.5%)^x

This gives

V(x) = 225000 * (1.035)^x

Next, we plot the graph of V(x)

See attachment

From the attached graph

V(x) = $296,282

Read more about exponential functions at:

https://brainly.com/question/11464095

#SPJ6

Find the value of each variable for the right triangles. Make sure all answers are in reduced radical form. Show your work.

Answers

By the Pythagorean theorem:

#1
[tex]t= \sqrt{13^2-12^2}= \sqrt{169-144}= \sqrt{25}=5 [/tex]

#2
[tex]a= \sqrt{12^2-9^2}= \sqrt{144-81}= \sqrt{63}= \sqrt{9*7}=3 \sqrt{7} [/tex]

#3
[tex]x= \sqrt{6^2+9^2}= \sqrt{36+81}= \sqrt{117}= \sqrt{9*13}=3 \sqrt{13} [/tex]

Answer:

i) t = 5

ii) a = 3√7

iii)  x =3√13

Step-by-step explanation:

We have right triangles.

Know the two sides of the triangle and need to find the third missing side.

In order to find the third side of the right triangle, we use pythagoras theorem.

It is,

(Hypotenuse)² = (base)² + (height)²

i)

13² = 12² + t²

169 = 144 + t²

t² = 25

t = 5.

ii)

12² = 9² + a²

144 = 81 + a²

144 - 81 = a²

a² = 63

a = √63

iii)

x² = 9² + 6²

x² = 81 + 36

x² = 117

x = √117

x = 3√13

Use the equation mg sin A = umg cos A to determine the angle at which a waxed wood block on an inclined plane of wet snow begins to slide. Assume the coefficient of friction, u, is 0.17. 9.6º 42º 48º 22º

Answers

Draw a diagram to illustrate the problem as shown below.

The weight, mg, is resolved into mg cos(A) and mg sin(A).
g = 9.8 m/s², acceleration due to gravity
μ = 0.17, static coefficient of friction

For motion to be initiated, 
mg sinA = μN
or
mgsin(A) = μmg cos(A)
sin(A)/cos(A) = μ
tan(A) = μ = 0.17
A = tan⁻¹ 0.17 = 9.648° = 9.6° (approx)

Answer:  9.6°

Final answer:

Using the friction equation mg sin A = μmg cos A and the given coefficient of friction (μ) of 0.17, the angle at which a waxed wood block begins to slide on wet snow is calculated to be approximately 9.6°.

Explanation:

To find the angle at which a waxed wood block on an inclined plane of wet snow begins to slide, we can use the equation mg sin A = μmg cos A, where A is the angle of inclination, m is the mass of the block, g is the acceleration due to gravity, and μ is the coefficient of friction. Since the mass (m) and gravity (g) are both common factors on each side of the equation, they can be canceled out, leaving us with tan A = μ, where tan A is the tangent of the angle A, and μ is the coefficient of friction (0.17 in this case). Solving for A gives us A = arctan(μ). So, A = arctan(0.17), which calculates to approximately 9.6°. This is the angle at which the block begins to slide.

1. How many ways can you arrange the letters in the word MOMMY
A. 20
B. 25
C. 60
D. 120

2. A bag of marbles has 3 red, 2 blue and 5 white marbles in it. What is the probability of reaching in and selecting a white marble ?

Answers

1. [tex]\frac{5!}{3!} [/tex] which is further simplified to [tex]5*4[/tex] which is 20.


2. [tex] \frac{5}{5+3+2}= \frac{5}{10}= \frac{1}{2} [/tex]




Find the value of x if B is between A and C, AB = 4x – 9, BC = 3x + 5 and AC = 17.

Answers

If A,B and C lie on the same line:

4x- 9 + 3x+5 = 17

7x = 21

x = 3
AB + BC = AC
4x - 9 + 3x + 5 = 17
7x - 4 = 17
add 4 to both sides
7x = 21
divide both sides by 7
x = 3

Joe can paint a fence in three hours; mary can paint it in two hours. how long will it take them to paint the fence if they work together?

Answers

776 h?
but what are the options for the answers?

A bag contains 20 candies: 3 cherry, 4 orange, 7 lemon, and 6 grape. if two candies are selected simultaneously, what is the probability that they are both the same flavor?

Answers

the answer is shown below

PLEASE HELP!!!! If a function, f(x) is shifted to the left four units, what will the transformed function look like?

Answers

If you shift f(x) to the left four units, then the coordinate axis effectively moves four units to the right. This "four units to the right" movement for the axis means that every x is replaced with x+4.

So that means f(x) turns into f(x+4)

For example, say we had the function f(x) = 5x^2 + 10x
Shifting f(x) four units to the left leads to
f(x) = 5x^2 + 10x
f(x+4) = 5(x+4)^2 + 10(x+4) ... notice the replacements in bold
f(x+4) = 5(x^2+8x+16) + 10(x+4)
f(x+4) = 5x^2 + 40x + 80 + 10x + 40
f(x+4) = 5x^2 + 50x + 120
Other Questions
The radius of the circle whose equation is (x + 4) + (y - 2) = 36 is 36 18 6 (mc) what path did booker t. washington recommend that african americans take to achieve racial equality? What type of column do the White House columns most closely resemble What must writers do when using language taken directly from an outside source A(n) ____ retains all of the existing computer settings possible including user files, applications, and application settings. active installation clean installation upgrade domain installation Gutenberg's printing press was not the starting pointing for modern history. a. True b. False 2. the arrival of cortes and pizarro changed history in the americas. a. True b. False 3. aztec, maya, and inca cultures are not important to the history of the americas. a. True b. False 4. the religions, beliefs and cultures of other civilizations and countries have affected american cultural life. a. True b. False 5. one can analyze history and conclude that it can be traced as a series of cause and effect relationships. a. True b. False Given the sequence: {2, 8, 32, 128, 512}, S12 = ??? A measure of how clean or polluted the air in a given region is on a particular day is the do elephants know how to swim in the 1900s, legal researcher Erin Brockovich helped win a lawsuit against Pacific Gas and Electric Company because it had been poisoning the water in the small town of Hinkley, California, for thirty years. Toxic Chromium 6 leached into the water system and sickened many Hinkley residents with ailments like liver damage and cancer. How would the illnesses of the Hinkley residents be classified? Find the value of x in the figure below. Round to the nearest tenth.6.720415 on a particular day, the Dow Jones had a rate of change of 2.8%. Which of the following statements must also be true?-The average of the 30 stocks in the Dow Jones increased.-The NASDAQ decreased.-The S&P 500 increased. -Every stock in the Dow Jones increased. ABC is a right triangle in which B is a right angle, AB= 1, AC=2 and BC= square root of 3. Cos C x sin A= Which type of lipoprotein transports newly digested fat from the intestine through the lymph and blood? The fraction 10/19 is in lowest terms 1. How could you test to see if an enzyme was completely saturated during an experiment? What is the slope of the line determined by any two solutions to the equation $\frac{2}{x}+\frac{3}{y} = 0$? Express your answer as a common fraction. Which of these is a sexual stereotype?A)on average, females weigh less than males. B)lesbians usually wear there hair short.C)women have twice as many X chromosomes as men.D)female hormone levels differ from those of males. What was one major way that the Central Pacific and Union Pacific railroad companies made a large profit in the 1800s?A.) They sold railroad lines back to the government at a profit.B.) They owned thriving businesses in the towns that developed along the railroad.C.) They built railroad monopolies and continually raised prices.D.) They sold pieces of land that were granted to them to build the railroad. If a wave has a wavelength of 9 meters and a period of 0.006, what is the velocity of the wave? Steam Workshop Downloader