Question

9. Given the function below, if (x,-4) is an element of the function, what is the value of x? F(x)=2x+16

Answer 1

Given the following function:

$F\mleft(x\mright)=2x+16​$

You can rewrite the function as following:

$y=2x+16​$

You know that an element of it is:

$\mleft(x,-4\mright)$

Notice that:

$y=-4$

Then, you can substitute this value into the function:

$-4=2x+16​$

Finally, solve for "x":

$\begin{gathered} -4-16=2x \\ -20=2x \\ \\ \frac{-20}{2}=x \\ \\ x=-10 \end{gathered}$

The answer is:

$x=-10$