find the difference quotient of f; that is, find (f(x + h)-f(x))/h, h≠0, for the following function. be sure…

find the difference quotient of f; that is, find (f(x + h)-f(x))/h, h≠0, for the following function. be sure to simplify. f(x)=x² - 7x + 8 (f(x + h)-f(x))/h =□ (simplify your answer.)
Answer
Explanation:
Step1: Find f(x + h)
Substitute (x+h) into (f(x)): [f(x + h)=(x + h)^2-7(x + h)+8=x^{2}+2xh+h^{2}-7x-7h + 8]
Step2: Calculate f(x + h)-f(x)
[ \begin{align*} f(x + h)-f(x)&=(x^{2}+2xh+h^{2}-7x-7h + 8)-(x^{2}-7x + 8)\ &=x^{2}+2xh+h^{2}-7x-7h + 8-x^{2}+7x - 8\ &=2xh+h^{2}-7h \end{align*} ]
Step3: Find the difference - quotient
[ \begin{align*} \frac{f(x + h)-f(x)}{h}&=\frac{2xh+h^{2}-7h}{h}\ &=\frac{h(2x + h-7)}{h}\ &=2x+h - 7 \end{align*} ]
Answer:
(2x+h - 7)