Which numbers cannot be used in place of the variable in each rational expression.

2y+1/y^2-y-6

(2y+1()/y^2-y-6)

= (2y+1)/[(y-3)(y+2)]

We cannot divide by zero.
When y = 3 or when y = -2 we would be dividing by zero

so x cannot be 3 or -2