Janet wants to solve the equation y + y2-5/y^2-1 = y^2+y+2/y+1 What should she multiply both sides of the equation by?

A) y

B) y^2-1

C) y+1

D) Y^2+y+2

Assuming the equation is

y + (y^2 - 5) / (y^2 - 1) = y^2 + y + 2 / (y+1),

We check the denominators, which are (y^2 - 1) and (y+1), then we take the least common denominator. Since y^2 - 1 = (y+1) (y-1), this means that the LCD is (y^2 - 1) itself, and this is what we should multiply by. Therefore the best answer is B.