Question

Simplify: ( y−7 × y−3 )−1

Answer 1

I believe the answer would be this:
-y^2 - 21

Answer 2

If you are of your writing the equation (y−7 × y−3 )−1 ,then you will solve it as follows:
[y -(7 x y) -3](-1) ==> [-y + (7 x y) + 3] ==>-y+7y+3 ==> 6y + 3 or 3(2y+1)