Answer
(a) $x^2+2xh+h^2-4x-4h+2$
(b) $2xh+h^2-4h$
(c) $2x+h-4$
Work Step by Step
(a) Given $f(x)=x^2-4x+2$, we have $f(x+h)=(x+h)^2-4(x+h)+2=x^2+2xh+h^2-4x-4h+2$
(b) $f(x+h)-f(x)=x^2+2xh+h^2-4x-4h+2-(x^2-4x+2)=2xh+h^2-4h$
(c) $\frac{f(x+h)-f(x)}{h}=2x+h-4$
