Question

计算：1）(a^2-1)/(-a)·(2ab^2)/(a^2-2a+1) 2）(x^2-3x)/(x+2)÷(x-3)/

Answer 1

1）(a^2-1)/(-a)·(2ab^2)/(a^2-2a+1) =(a+1)(a-1)·(-2b^2)/(a-1)^2=-2b^2(a+1)/(a-1) 2）(x^2-3x)/(x+2)÷(x-3)/(x^2-4)=x(x-3)/(x+2)*(x+2)(x-2)/(x-3)=x(x-2)=x^2-2x