Best thing to do here is to separate the numerator into 2 separate expressions, each one over the denominator. Like this: [tex] \frac{8x^2y^2}{4xy}- \frac{4xy}{4xy} [/tex]. In the expression on the left, 8/4 = 2, x^2/x = x, y^2/y = y. That is 2xy. The right side is equal to 1, so the final simplfication is 2xy-1
