find the difference quotient of f; that is, find $\frac{f(x + h)-f(x)}{h}$, h ≠ 0, for the following…

find the difference quotient of f; that is, find $\frac{f(x + h)-f(x)}{h}$, h ≠ 0, for the following function. be sure to simplify.\n\n$f(x)=x^{2}-4x + 6$\n\n$\frac{f(x + h)-f(x)}{h}=square$ (simplify your answer.)
Answer
Explanation:
Step1: Find f(x + h)
Substitute x+h into f(x): [ \begin{align*} f(x + h)&=(x + h)^2-4(x + h)+6\ &=x^{2}+2xh+h^{2}-4x-4h + 6 \end{align*} ]
Step2: Calculate f(x + h)-f(x)
[ \begin{align*} f(x + h)-f(x)&=(x^{2}+2xh+h^{2}-4x-4h + 6)-(x^{2}-4x + 6)\ &=x^{2}+2xh+h^{2}-4x-4h + 6-x^{2}+4x - 6\ &=2xh+h^{2}-4h \end{align*} ]
Step3: Find the difference quotient
[ \begin{align*} \frac{f(x + h)-f(x)}{h}&=\frac{2xh+h^{2}-4h}{h}\ &=\frac{h(2x + h-4)}{h}\ &=2x+h - 4 \end{align*} ]
Answer:
$2x+h - 4$