Answer
-1/(x² + xh)
-1/xw
Work Step by Step
f(x) = 1/x
f(x + h) = 1/(x + h)
[f(x + h) - f(x)]/h = [1/(x + h) - 1/x]/h = {[x - (x + h)]/[x(x + h)]}/h =
= [-h/(x² + xh)]/h = -1/(x² + xh)
f(w) = 1/w
[f(w) - f(x)]/(w - x) = (1/w - 1/x)/(w - x) = [(x - w)/xw]/(w - x) =
= -1/xw
