Note that we have a common denominator at the top....so this is just
[ 1 - x^2 ] / 4
Notice that x can be wriiten as x / 1
So we have
[ 1 - x^2 ] / 4 ÷ [ x / 1 ]
Invert the second fraction and multiply
( 1 - x^2) 1 (1 - x^2)
_______ * ____ = _________
4 x 4x
