Find the difference quotient of LaTeX:  \displaystyle f(x)=7 - 3 x .

The difference quotient is LaTeX:  \displaystyle \frac{f(x+h)-f(x)}{h} . Evaluating LaTeX:  \displaystyle f(x+h)=- 3 h - 3 x + 7 and expanding gives LaTeX:  \displaystyle f(x+h)=- 3 h - 3 x + 7 Evaluating the difference quotient gives LaTeX:  \displaystyle \frac{(- 3 h - 3 x + 7)-(7 - 3 x)}{h} Simplifying gives LaTeX:  \displaystyle \frac{- 3 h}{h}=-3