Question

Simplify by removing factors of 1.
y^2-1/1-y

Answer 1

The numerator is difference of squares:

(y-1)(y+1)/(1-y)

Simplify from there

Answer 2

I get -1

Answer 3

But I think that is wrong

Answer 4

How did you get negative 1?

Answer 5

\[\frac{(y-1) (y+1)}{1-y} \]\[-\frac{(y-1) (y+1)}{-(1-y)} \]\[-\frac{(y-1) (y+1)}{(y-1)} \]\[-(y+1) \]