(80pts) The ratio of the number of A's in the class to B's in the class was 2:5. How many people got A's if there were 40 people who got B's?

Answer:

22. Perimeter = 52 units

     Area = 160 Square Units

23. Notation form :  [tex] 2 \times 10^{5}[/tex]

     Standard Form : 200000

Step-by-step explanation:

22.

The formula for perimeter is

P = 2 (length + Width )

  = 2 ( 2x+3x+1)

  =  2(5x+1)

The Formula for Area of a rectangle is

A= length x width

A= [tex]2x \times (3x+1)[/tex]

A=[tex]6x^2+2x[/tex]

Now we have to find the Perimeter and Area for x = 5

P = 2(5 x 5 +1)

P= 2(26)

P=52 units

A= 6 x 5 x 5 + 2 x 5

A= 150 + 10

A= 160 square units

23.

A. By using rule of exponents , we can determine that both the results will be same.

B.

Miriam's calculation

[tex]\frac{2.8 \times 10^{9}}{1.4 \times 10^{4}}[/tex]

[tex]\frac{2.8}{1.4} \times 10^{9-4}[/tex]

[tex]2 \times 10^5[/tex]

Priya's calculation

[tex]\frac{2.8 \times 10^{2}}{1.4 \times 10^{-3}}[/tex]

[tex]\frac{2.8}{1.4} \times 10^{2-(-3)}[/tex]

[tex]2 \times 10^5[/tex]

Standard notation

[tex]2 \times 10^5 = 200000[/tex]

Answer:

The perimeter is 24 sq inches.

Step-by-step explanation:

In order to find perimeter, you must add together all the sides. So the equation would be (LxW)2 , or just Length plus Length plus Width plus Width. Therefore, it is either (7x5)2 or 7 + 7 + 5 + 5 which both equal 24 sq inches. Hope this helps!

The perimeter of a rectangle with an area of 35 square inches, length of 7 inches, and width of 5 inches is calculated using the formula P = 2l + 2w, resulting in a perimeter of 24 inches.

To calculate the perimeter of a rectangle when given the area and the dimensions, we use the formula P = 2l + 2w, where 'P' represents the perimeter, 'l' is the length, and 'w' is the width of the rectangle. If we know the length is 7 inches and the width is 5 inches, we can plug these values into the formula to find the perimeter:

P = 2(7) + 2(5) = 14 + 10 = 24 inches.

Therefore, the perimeter of the rectangle with an area of 35 square inches, length of 7 inches, and width of 5 inches is 24 inches.

Brackish water is shown as being 0.05 - 3%

2% falls in this range, so it would be Brackish water.

Answer:

the circumference of the outer edge of the path around the pool is 113.04 ft

Step-by-step explanation:

Hello, I think I can help you with this

the circumference is given by:

S=2π*r

where, S is the length of the circumference,π=3.14159.., r= radius

Step one

define the radius

the total radius of the pool and the path is

radius=15 ft + 3 ft

radius=18 ft

Step two

π=3.14

radius=18 ft

put the values into the equation

S=2π*r

S=2*3.14*18 ft

S=113.04 ft

the circumference of the outer edge of the path around the pool is 113.04 ft

I hope it helps, Have a nice day.

Answer:

5km=5000m

Because the rate to this is: 1:1000

Answer:

Step-by-step explanation:

[tex]\text{5 km}*\dfrac{1000 m}{1 km} = 5000m[/tex]

Notice that the units cancel out. You always want that to happen. Depending on your grade level and your teacher, you can avoid the proportion by doing the question this way. Always make sure you arrange it so that 1 set of units will cancel.

Answer:

[tex]\large\boxed{x=-4\ \vee\ x=7}[/tex]

Step-by-step explanation:

[tex]x^2-3x-28=0\\\\x^2+4x-7x-28=0\\\\x(x+4)-7(x+4)=0\\\\(x+4)(x-7)=0\iff x+4=0\ \vee\ x-7=0\\\\x+4=0\qquad\text{subtract 4 from both sides}\\x=-4\\\\x-7=0\qquad\text{add 7 to both sides}\\x=7[/tex]

Answer:

the mode is 3 and 5

Step-by-step explanation:

If there is a tie between the modes, it is called bimodal. There can be 2 modes in a data set.

Answer:

the mode is 3 AND 5 which means it is a bimodal

Step-by-step explanation:

Answer:

hope it's help you.

Mark me at brainlist please

To find what y is when x = 7 plug 7 into x in the equation and solve

y = 7 - 3

y = 4

When x is 7, y is 4

To find what x is when y = 1 plug 1 into y  in the equation and solve

1 = x - 3

1 + 3 = x + (-3 + 3)

4 = x + 0

4 = x

When y is 1, x is 4

To find what x is when y = 7 plug 7 into y in the equation and solve

7 = x - 3

7 + 3 = x + (-3 + 3)

10 = x + 0

10 = x

When y is 7, x is 10

Hope this helped!

~Just a girl in love with Shawn Mendes

Answer:

see explanation

Step-by-step explanation:

To find the x- intercepts let y = 0, that is

(x - 4)(x + 2) = 0

Equate each factor to zero and solve for x

x - 4 = 0 ⇒ x = 4

x + 2 = 0 ⇒ x = - 2

x- intercepts are x = - 2 and x = 4

The vertex lies on the axis of symmetry which is located at the midpoint of the x- intercepts, thus

[tex]x_{vertex}[/tex] = [tex]\frac{-2+4}{2}[/tex] = 1

Substitute x = 1 into the equation for corresponding value of y

y = (1 - 4)(1 + 2) = - 3 × 3 = - 9

vertex = (1, - 9)

The x-intercept of the line will be  x = 4 and x = -2 and Vertex = (1, - 9).

The x-intercepts are the points where the graph intersects the x-axis. The vertex is the point that defines the minimum or maximum of a parabola.

We have,

y = (x - 4) (x + 2)

Now,

So, to get the x-intercept,

Put y = 0,

i.e.

0 = (x - 4) (x + 2)

NOw,

x - 4 = 0

⇒ x = 4,

And,

x + 2 = 0

⇒ x = -2

So,

x-intercepts are x = 4 and x = -2.

Now,

To get the vertex ,

For vertex,

The vertex lies on the axis of symmetry which is located at the midpoint of the x- intercepts, thus

Vertex for x [tex]=\frac{-2+4}{2}=1[/tex]

Now,

Substitute x = 1 into the equation,

i.e.

y = (1 - 4)(1 + 2)

= - 3 × 3 = - 9

So,

Vertex = (1, - 9)

Hence, we can say that the x-intercept of the line will be  x = 4 and x = -2 and Vertex = (1, - 9)

To know more about x-intercept and Vertex forms click here

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Answer:

Let the speed of the train be x km/h.

Case 1:

Distance = 288 km

Speed = x km/h

Time = Distance/Speed

= 288/x h

Case 2:

Distance = 288 km

Speed = (x+4) km/h

Time = 288/x + 4 h

Since 288/x > 288/x + 4

288/x - 288/x+4 = 1

288[1/x - 1/x+4 ] = 1

[ x + 4 - x / x(x + 4) ] = 1/288

[4 / x^2 + 4x ] = 1/288

x^2 + 4x = 1152

x^2 + 4x - 1152 = 0

x^2 + 36x - 32x - 1152 = 0

x(x + 36) - 32(x + 36) = 0

(x + 36)(x - 32) = 0

x + 36 = 0 , x - 32 = 0

x = -36 , x = 32

x = -36 , rejected since speed cannot be negative.

Therefore , speed of the train = 32 km/h

Answer:

x = 90°

Step-by-step explanation:

The diagonals of the kite AC and BD are perpendicular to each other

Hence x = 90°

Answer: Eden correctly solved the problem.

Step-by-step explanation:

Without specific problem details, it is impossible to provide an accurate answer on who completed the problem correctly and what mistakes the others made.

Without the details of the problem that Emma, Erin, and Eden completed, it is impossible to correctly determine who solved the problem right and what errors the other two students made in their calculations. However, usually, such questions involve displaying similar problems worked out by different students and based on the solution, we would determine who was correct and identify the errors on the part of the other students.

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Answer:

2) 3

Step-by-step explanation:

Graphing the best-fit quadratic curve for the data-set can be done using Ms. Excel Application.

The first basic step is to enter the data into any two adjacent columns of the excel workbook. Highlight the two columns where the values have been entered, click on the insert tab and then select the x,y scatter-plot feature. This will create an x,y scatter-plot for the data.

Next, click on the Add Chart Element feature and add a polynomial trend-line of order 2 which is basically a quadratic curve. Finally, check the display equation on chart box. This step will plot the quadratic curve as well as give the equation of the best-fit quadratic curve.

The attachment below shows the best-fit quadratic curve to the data-set and its corresponding equation.

A good approximation for the value of c from the equation is thus 3. This is simply the y-intercept of the curve. 3.21 is closer to 3.

Answer:

Hourly fee = $15 per hour

Step-by-step explanation:

Royce is taking violin lessons. The instructor charges an initial fee and an hourly fee. The amount Royce pays based on the length of his lesson is shown in the graph below.

To find out hourly fee , we use any two points from the given graph

Hourly fee is the slope of the line

LEts pick (2,52)  and (3,67)

Slope = [tex]\frac{y_2-y_1}{x_2-x_1} = \frac{67-52}{3-2} = 15[/tex]

Hourly fee = $15 per hour

Answer:

$15

Step-by-step explanation:

I play the violin and my lessons i get from school ive been playing for 4 and a half years now i no everything and i can surely  tell you its $15

Answer:

2,294.66 square inches

Step-by-step explanation:

The area of an octagon is given by the formula:

A = 2 * a² * ( 1 + √2 )

So, if we input the numbers we have:

A = 2 * 21.8² * ( 1 + √2 )

A = 2 * 475.24 * (2.4142)

A = 2,294.66 square inches

As you can see, if you double the side of an octagon, its area will quadruples, which is logic since the one variable in the calculation of the area is the side's length... that is squared.  So, if you double it, that double factor is squared.

It's as if we had written  

A = 2 * (10.9 * 2)² * ( 1 + √2 )

A = 2 * (10.9² * 2²) * ( 1 + √2 )

The answer is:

[tex]Sin(A)=0.93[/tex]

To solve the problem, remember to set your calculator in "degree mode"

So, we are given that the angle A is equal to 68°

So, we have that:

[tex]Sin(A)=Sin(68\°)=0.93[/tex]

Hence, we have that:

[tex]Sin(A)=0.93[/tex]

Have a nice day!

-7x-3x > -14-6; -10x > -20 divide both sides by -10; x < 2; Solutions are: A)-10, C) -5, E) -3, G)0

Answer: C. the circumferences of the base of each cylinder must be the same

Step-by-step explanation:

Check the picture below.

so we know that the area of the base of the 1st cylinder is 452.16, and the radius of the 2nd cylinder is 12, hmmm what is the radius of the 1st cylinder anyway?

[tex]\bf \textit{area of a circle}\\\\ A=\pi r^2~~ \begin{cases} r=radius\\ \cline{1-1} A=452.16 \end{cases}\implies 452.16=\pi r^2\implies \cfrac{452.16}{\pi }=r^2 \\\\\\ \stackrel{\pi =3.14}{\cfrac{452.16}{3.14 }}=r^2\implies 144=r^2\implies \sqrt{144}=r\implies 12=r[/tex]

low and behold, the radius of the 1st one is 12 as well, so both cylinders have the same radius.  Let's recall the volume of a cylinder is V = πr²h.

now if they can just have the same height, they'd both have the same volume.

A is the correct answer. Factor by grouping

Answer:B

Step-by-step explanation:

Is easy

Answer:

2 1/3 yds

Step-by-step explanation:

We need to subtract 1 1/6 yds from 3 1/2 yds to answer this question.

The LCD is 6:

3 1/2 - 1 1/6 becomes 3 3/6 - 1 1/6.  This results in 2 2/6, or 2 1/3, yds

Jim must purchase 2 1/3 yds more of burlap.

For this case we must subtract the amounts to know how many yards of burlap Jim should buy:

[tex]3 \frac {1} {2} = \frac {6 + 1} {2} = \frac {7} {2}\\1 \frac {1} {6} = \frac {6 + 1} {6} = \frac {7} {6}[/tex]

We subtract the amounts:

[tex]\frac {7} {2} - \frac {7} {6} = \frac {42-14} {12} = \frac {28} {12} = \frac {14} {6} = \frac { 7} {3}[/tex]

We convert to a mixed number:

[tex]2 \frac {1} {3}[/tex]

ANswer:

Option B

Answer:

A firm determines its profit by subtracting "Total Cost" from "Total Revenue".

Step-by-step explanation:

We have been given a statement "A firm determines its profit by subtracting _____ from ______. Now we need to fill the blanks with suitable words.

We know that there are some initial costs associated with production of any product. So to get the profit, we need to subtract the cost that that is spent during production of the product from total sales.

Hence final answer can be written as:

A firm determines its profit by subtracting "Total Cost" from "Total Revenue".

Given,

[tex]y = \frac{ - 2}{7} x \\ \frac{2}{7} x + y = 0 \\ \frac{2x + 7y}{7} = 0 \\ 2x + 7y = 0[/tex]

Now,

slope of the line(m) =

[tex] \frac{- coefficient \: of \: x }{coefficient \: of \:y} \\ = \frac{ -2 }{7} [/tex]

Answer:

-2⁄7

Step-by-step explanation:

In the Slope-Intercept Formula, y = mx + b, m is the Rate of Change [Slope]. So, in this case, our slope is -2⁄7.

I am joyous to assist you anytime.

Answer:

[tex]\large\boxed{-\dfrac{4}{2}=-2}[/tex]

Step-by-step explanation:

[tex]a_1,\ a_2,\ a_3,\ a_4,\ ...-\text{geometric sequence}\\\\\dfrac{a_2}{a_1}=\dfrac{a_3}{a_2}=\dfrac{a_4}{a_3}=...-\text{common ratio}\\\\======================\\\\\text{We have}\\\\-2,\ 4,\ -8,\ 16,\ -32,\ ...\\\\\text{The common ratio:}\\\\\dfrac{4}{-2}=-2\\\\\dfrac{-8}{4}=-2\\\\\dfrac{16}{-8}=-2\\\\\dfrac{-32}{16}=-2[/tex]

Answer: D) y = -3 sin 8x

Step-by-step explanation:

The given graph has an amplitude of 3 (A = 3) and a period of π/2 (B = 4).

Therefore, the equation of the graph is: y = 3 sin 8x    Option A

Option B is a reflection of Option A, shifted π units to the left

Option C is Option A, shifted 2π units to the right

Both Options B and C are equivalent to Option A

Option D is a reflection of Option A but since there is no horizontal shift, it cannot be equivalent to Option A

Answer:

-20

Step-by-step explanation:

Unfortunately, there is no shortcut to solve these... you have to do the work, iteration by iteration.

A recursive function is a function that calls itself and takes as input the output of the previous call.

a = -2 a + 4

a1: 1

a2: -2 (1) + 4 = -2 + 4 = 2

a3: -2 (2) + 4 = -4 + 4 = 0

a4: -2 (0) + 4 = -0 + 4 = 4

a5: -2 (4) + 4 = -8 + 4 = -4

a6: -2 (-4) + 4 = 8 + 4 = 12

a7: -2 (12) + 4 = -24 + 4 = -20

so a7 = -20

Answer: The answer would be D. 64

Step-by-step explanation: Understanding that the question noted that the second rectangle was dilated from PQRS, which has a perimeter of 16. With the coordinates of point P for the first rectangle being (2,0.5) whilst the second rectangle has point P at (8,2). To figure out the perimeter, divide point P from the second rectangle with point P from the first. The result would be 4. Thus, the scale factor is 4, which you then multiply the perimeter of PQRS by, which was 16. 16 times 4 equals 64.

Answer: D

Explanation: It is D

54 students on each bus

if we take 125 to be the 100%, what is 57 off of it in percentage?[tex]\bf \begin{array}{ccll} amount&\%\\ \cline{1-2} 125&100\\ 57&x \end{array}\implies \cfrac{125}{57}=\cfrac{100}{x}\implies 125x=5700 \\\\\\ x=\cfrac{5700}{125}\implies x = 45.6[/tex]

There are 125 people and 57 of the people have pets. What percent of people have pets.

First, we need to understand what the question is asking us to do. We know that there are 125 people altogether and only 57 of the people have pets. We are trying to figure out what percent of the people have pets.

The fraction [tex]\frac{57}{125}[/tex] is representing the 57 people who have pets out of all the people. To find what percent of people have pets, we have to change [tex]\frac{57}{125}[/tex] to a percent.

57 ÷ 125 = 0.456

0.456 × 100 = 45.6%

Therefore, 45.6% of people have have pets.