Solve for x: 8x + 10 - 5x = 15.

The answer is C.

The figures in your problem are inconsistent with the data. 
The sample std deviation is not and cannot be .04 (4%). 
the sample std dev is sqrt[(.47)(1-.47)/400]=.02495. 
The margin of error from your CI is .474 -.47= .004 (very small). 
This would represent .02495/.004= 6.24 std dev. from expected, which would have a very 
high level of confidence (99.97.. %). Something is likely wrong with the figures in your problem.

Answer: 95%

Step-by-step explanation:

x = ones

y = fives

x+y = 14 total bills

 rewrite as x = 14-y

1x +5y = 50

1(14-y) +5y = 50

14-1y +5y = 50

14 +4y = 50

4y = 36

 y = 36/4 = 9

 x = 14-y = 14-9 = 5

 9+5 = 14

9x5 = 45 +5x1 = 50

 he had 9 fives and 5 ones

Answer:

There were 5 bills of '1' and 9 bills of '5'.

Step-by-step explanation:

let the number of '1' bill be x

let the number of '5' bill be y.

Total number of bills = 14

x + y = 14 ..[1]

Worth of 14 bills = 50

So,[tex]x\times 1+y\times 5=\$50[/tex]

[tex]x+5y=50[/tex]..[2]

x + y = 14

x = 14 - y

Putting value of x in [2]:

[tex]14- y +5y=50[/tex]

[tex]y=\frac{50-14}{4}=9[/tex]

y = 9

x = 14-y = 14 - 9 = 5

There were 5 bills of '1' and 9 bills of  '5'.

Answer:B. {x| x = –7, –6, 2, 11, 3}.

Answer:

For f(x)=2x² graph, the answer is A.

Step-by-step explanation:

Answer:  A. Horizontal compression by factor 1/3, vertical stretch by factor 2, then a reflection through the x-axis

Step-by-step explanation:

Since, If there is a function, y= a cos bx

Then a shows vertical stretch while b shows horizontal compression.

Here, Given function, y= cos x

After transformation, It is giving y = -2 cos 3x

therefore here is a horizontal compression occurs with factor 1/3.

Also Negative sign shows there also did reflection through x-axis.

And, It also, stretched vertically by factor 2. ( also shown in the below graph)

Thus, Option A) is correct.      

1)   8k - (6k - 4) = 10

         [tex]\mathsf{8k-6k+4=10}\\\\ \mathsf{2k=10-4}\\\\ \mathsf{2k=6}\\\\ \underline\mathsf{k=\dfrac{6}{2}=3}}[/tex]

2)    -12x + 8 + 5x = 36

         [tex]\mathsf{-12x+8+5x=36}\\\\ \mathsf{-12x+5x=36-8}\\\\ \mathsf{-7x=28}\\\\ \mathsf{x={28}{-7}}\\\\ \underline{\mathsf{x=-4}}[/tex]

3)    -2y + 4 = 8y - 6

         [tex]\mathsf{-2y+4=8y-6}\\\\ \mathsf{-2y-8y=-6-4}\\\\ \mathsf{-10y=-10}\\\\ \mathsf{y=\dfrac{-10}{-10}}\\\\ \underline{\mathsf{y=1}}[/tex]

We have that the -18 is a rational quantity due to the fact it can be expressed as a fraction of two integers. It's additionally an integer.

Rational number & Integer

Generally

The subsets of the actual numbers are as follows

-18 is a rational quantity due to the fact it can be expressed as a fraction of two integers. It's additionally an integer.

For more information on Numbers visit

https://brainly.com/question/21094767

It would take Brian 20 hours to build the model car on his own.

To determine the time it would take Brian to build the model car on his own, we can follow these steps:

1. Let's denote the time it takes John to build the model car as J hours.

2. Since it takes Brian 15 hours longer than John, we can express the time it takes Brian as J +15 hours.

3. If they work together, they can build the model car in 4 hours. This means that in 1 hour, they complete [tex]\(\frac{1}{4}\)[/tex] of the job together.

4. In 1 hour, John completes [tex]\(\frac{1}{J}\)[/tex] of the job, and Brian completes [tex]\(\frac{1}{J + 15}\)[/tex] of the job.

5. So, the equation representing the rate at which they work together is:

[tex]\[ \frac{1}{J} + \frac{1}{J + 15} = \frac{1}{4} \][/tex]

6. Now, we solve this equation to find J, the time it takes John to build the model car on his own.

7. Once we find J, we can find J+15  which represents the time it takes Brian to build the model car on his own.

So, the equation representing the rate at which they work together is:

[tex]\[ \frac{1}{J} + \frac{1}{J + 15} = \frac{1}{4} \][/tex]

To solve this equation, we can multiply both sides by the least common denominator, which is [tex]\( 4J(J + 15) \)[/tex], to clear the fractions:

[tex]\[ 4(J + 15) + 4J = J(J + 15) \][/tex]

Expanding and simplifying:

[tex]\[ 4J + 60 + 4J = J^2 + 15J \]\[ 8J + 60 = J^2 + 15J \]\[ J^2 + 15J - 8J - 60 = 0 \]\[ J^2 + 7J - 60 = 0 \][/tex]

Now, we have a quadratic equation. We can solve this equation using factoring, completing the square, or the quadratic formula. Let's use factoring:

[tex]\[ (J - 5)(J + 12) = 0 \][/tex]

Setting each factor equal to zero:

[tex]\[ J - 5 = 0 \] or \( J + 12 = 0 \)[/tex]

Solving each equation:

[tex]For \( J - 5 = 0 \), we get \( J = 5 \).For \( J + 12 = 0 \), we get \( J = -12 \).[/tex]

Since time cannot be negative, we discard the negative solution.

Now that we have found J=5 hours, which represents the time it takes John to build the model car on his own, we can find [tex]\( J + 15 = 5 + 15 = 20 \)[/tex] hours.

Final answer:

To determine the angle of elevation x, we use the sine function with the opposite side (20 ft) and the hypotenuse (24 ft) to get sin(x) = 20/24, and by taking the arcsin of the result, we find that x ≈ 56.4° when rounded to the nearest tenth of a degree.

Explanation:

To find x, the angle of elevation of the ramp, we can use trigonometric functions. Since we have the length of the ramp (hypotenuse) and the height of the platform (opposite side) in a right-angled triangle, we can use the sine function, which is defined as the ratio of the opposite side to the hypotenuse.

Using the sine function: sin(x) = opposite/hypotenuse = 20/24.

We first calculate the ratio: sin(x) = 20/24 = 0.8333.

To find the angle x, we take the inverse sine (also known as arcsine) of the ratio: x = arcsin(0.8333).

Using a calculator set to degree mode, we find that x ≈ 56.4° when we round to the nearest tenth of a degree.

The corresponding output for an input value of 3 is -1. Hence f(3) is -1

from the mapping function given, the domain values are the input values of the function while the range is the output.

To get the value of f(3), we need to check the corresponding output when the input variable is 3.

From the given one-on-one mapping, we can see that the corresponding output for an input value of 3 is -1. Hence f(3) is -1

Learn more here; https://brainly.com/question/3373678

1 inch = 2.54 cm

 so multiply 27 by 2.54

27 x 2.54 = 68.58 cm long

To convert 27 inches to centimeters, multiply 27 by the conversion factor of 2.54 cm per inch, resulting in 68.58 centimeters.

The student has asked how long a board that is 27 inches long is in centimeters, given the conversion factor that 1 inch is equal to 2.54 centimeters. To convert inches to centimeters, you multiply the length in inches by the conversion factor. In this case, you would multiply 27 inches by 2.54 to find the length in centimeters.

Here is the calculation:
27 inches x 2.54 cm/inch = 68.58 centimeters.

Therefore, a board that is 27 inches long is 68.58 centimeters long.