Question

In the following function: f(x) = 2x + 2, list the input values (x) that produce the output values 8, 12, and 16. A) 1,2,3 B) 3,5,7 3,4,5 D) 4,6,8

Answer 1

To find the input value that corresponds to each output value, replace f(x) for each of the given output values and solve for x, that is the input value:

$\begin{gathered} f(x)=2x+2 \\ 8=2x+2 \\ 8-2=2x \\ \frac{6}{2}=x \\ x=3 \\ 12=2x+2 \\ 12-2=2x \\ \frac{10}{2}=x \\ x=5 \\ 16=2x+2 \\ 16-2=2x \\ \frac{14}{2}=x \\ x=7 \end{gathered}$

The input values that produce 8,12 and 16 are: B. 3,5,7.