Chapter 14.1, Problem 1WE

To determine

To find: The image of 8 and the pre image of $13$ if the function is $f:x=5x-7$ .

Answer to Problem 1WE

The image of 8 is 33 and the pre image of 13 is 4 for the function.

Explanation of Solution

Calculation:

Consider the given function $f:x=5x-7$ . It can be also written as $f\left(x\right)=5x-7$ .

To calculate the image, substitute 8 for $x$ in the function.

  $\begin{array}{c}f\left(8\right)=5\times 8-7\\ =40-7\\ =33\end{array}$

To calculate the pre image, equate the function with the given value.

  $\begin{array}{c}f\left(y\right)=13\\ 5y-7=13\\ y=4\end{array}$

Therefore, the image of 8 is 33 and the pre image of 13 is 4 for the function.