Introductory Algebra for College Students (7th Edition)

$-y-3$
Simplifying Rational Expressions 1. Factor the numerator and the denominator completely. 2. Divide both the numerator and the denominator by any common factors. --- Numerator $:$ search for two factors of $-12$ whose sum is $-1$ ... these are $-4$ and $3$ $y^{2}-y-12=(y-4)(y+3)$ Denominator = $-(y-4)$ Expression = $\displaystyle \frac{(y-4)(y+3)}{-(y-4)}$ ... divide both with the common factor: $(y-4)$ Expression = $\displaystyle \frac{y+3}{-1}$ = $-(y+3)$ = $-y-3$