Answer
$\text{(a) }40$
$\text{(b) }88$
$\text{(c) }-40$
$\text{(d) }(40,\infty)$
$\text{(e) }(-\infty,88]$
$\text{(f) }(-40,88)$
Work Step by Step
Use the given figure, we have:
(a) For $f(x)=50$, we can identify $x=40$
(b) For $f(x)=80$, we can identify $x=88$
(c) For $f(x)=0$, we can identify $x=-40$
(d) For $f(x)\gt50$, we have $x\gt 40$ or $(40,\infty)$
(e) For $f(x)\le80$, we have $x\le 88$ or $(-\infty,88]$
(f) For $0\lt f(x)\lt80$, we have $-40\lt x\lt 88$ or $(-40,88)$
