1、[x÷(2-x)]-[(4-x²)÷(x²-4x+4)] 2、[b÷(a²-ab)+a÷(b²-ab)]÷[(a-b)÷(ab)]

1、[x÷(2-x)]-[(4-x²)÷(x²-4x+4)] 2、[b÷(a²-ab)+a÷(b²-ab)]÷[(a-b)÷(ab)]

1. The original formula = - X / (X-2) + (X-2) (x + 2) / (X-2) & sup2; = - X / (X-2) + (x + 2) / (X-2) = (- x + X + 2) / (X-2) = 2 / (X-2) 2, the original formula = [B / a (a-b) - A / b (a-b)] / [(a-b) / AB] = [(B & sup2; - A & sup2;) / AB (a-b)] × [AB / (a-b)] = - [(a + b) (a-b) / (a-b)] × [1 / (a-b)] = - (a + b) = (a-b) = (a + b) = (a-b) = (a + b) = (a-b) = (a-b) = (a-b) = (a-