Answer
- 18
Work Step by Step
see: Rules for Limits
Let $a, A$, and $B$ be real numbers,
and let $f$ and $g$ be functions such that
$\displaystyle \lim_{x\rightarrow a}f(x)=A$ and $\displaystyle \lim_{x\rightarrow a}g(x)=B$.
2. $\displaystyle \lim_{x\rightarrow a}[f(x)\pm g(x)]=\lim_{x\rightarrow a}f(x)\pm\lim_{x\rightarrow a}g(x)=A\pm B$
(The limit of a sum or difference is the sum or difference of the limits.)
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$\displaystyle \lim_{x\rightarrow 4}[f(x)-g(x)]=\lim_{x\rightarrow 4}f(x)-\lim_{x\rightarrow 4}g(x)$
$=9-27=-18$
