## Calculus 8th Edition

$-\infty$
$x\rightarrow 5^{-}$ means that the values of x are positive (close to 5) and being left of 5, slightly less than 5. For any of these x, the numerator is positive and the denominator is negative, as it approaches $0$ from the negative side So, $\displaystyle \lim_{x\rightarrow 5^{-}}\frac{x+1}{x-5}=-\infty$