You can put this solution on YOUR website! Denominators cannot be zero (because division by zero is undefined). So set your denominator to zero:
and solve the equation. This is a quadratic equation so we will factor it:
x*(2x+1) = 0
From the Zero Product Property we know that one of these factors must be zero. So:
x = 0 or 2x+1 = 0
Solving the second equation we get:
x = 0 or x = -1/2
These are the values of x that make the denominator zero so these are the values that x cannot have!