Chapter 8.7, Problem 5E

To determine

To find:

The value of $x$ , when $f(x)=67$ .

Answer to Problem 5E

The value of $x$ , when $f(x)=67$ would be $9$ .

Explanation of Solution

Given:

A function: $f(x)=7x+4$

Calculation:

To find the value $x$ , when $f(x)=67$ , we will replace $f(x)$ with $67$ in our given function as shown below:

  $\begin{array}{l}f(x)=7x+4\left(\text{Given function}\right)\\ 67=7x+4\left(\text{Substituting }f(x)=67\right)\\ 7x+4=67\left(\text{Switching sides}\right)\\ 7x+4-4=67-4\left(\text{Subtracting 4 from both sides}\right)\\ 7x=63\\ \frac{7x}{7}=\frac{63}{7}\left(\text{Dividing both sides by 7}\right)\\ x=9\end{array}$

Therefore, the value of $x$ , when $f(x)=67$ would be $9$ .