Remark
Let y = f(x)
Now we have y = x/4
It is much easier to solve in this form
y = - 8
- 8 = x/4 Multiply both sides by 4
-8 * 4 = (x/4) * 4
- 32 = x <<<< Answer
In other words, equate x/4 and -8 and solve for x: Mult. both sides of this equation by 4: x = -32
