If $g$ is a differentiable function, find an expression for the derivative of each of the following functions:

In submitting the answers below, write $g(x)$ as $g$, and write $g'(x)$ as $h$.

(a) If $y = xg(x)$, then $y'=$

(b) If $y = x/g(x)$, then $y'=$

(c) If $y = g(x)/x$, then $y'=$