I'm trying to solve the equality
I can't work out how to get the second solution of x > -1
You messed up in your second step.
When you multiply both sides of an inequality by a negative number (which happens when x is less than -1) you have to flip the sign, meaning that the second step would actually yield two inequalities:
and
Notice thatbecause then you would have division by zero, which isn't allowed.