Answer
(a) $-2,3$.
(b) $(-\infty,-2]\cup[3,\infty)$.
(c) $(-2,3)$.
Work Step by Step
(a) Use the given graph, we can identify the intersects $(-2,5),(3,5)$, thus the solutions to $f(x)=g(x)$ are $x=-2,3$.
(b) $f(x)\ge g(x)$ happens when $x\le-2$ or $x\ge3$, that is $(-\infty,-2]\cup[3,\infty)$.
(c) $f(x)\lt g(x)$ happens when $-2\lt x\lt3$ or $(-2,3)$.