Answer
Such expressions equal (simplify to) $-1.$
Work Step by Step
Simplifying Rational Expressions with Opposite Factors in the Numerator and Denominator
The quotient of two polynomials that have opposite signs and are additive inverses is $-1$.
Example
$\displaystyle \frac{x-1}{1-x}=$ ... recognize that $x-1=-(1-x)$
$=\displaystyle \frac{-(1-x)}{(1-x)}$ = .... opposite factors (can be reduced)
$=-1$
Such expressions equal (simplify to) $-1.$
