通分:(1)2a/a^2-3a,3/a^2-9 (2)x+2/x^2-2x,x-1/x^2-4x+4

问题描述:

通分:(1)2a/a^2-3a,3/a^2-9 (2)x+2/x^2-2x,x-1/x^2-4x+4

(1)
2a/a^2-3a=2a(a+3)/a(a+3)(a-3)
3/a^2-9=3a/a(a+3)(a-3)
(2)
x+2/x^2-2x=(x+2)(x-2)/x(x-2)²
x-1/x^2-4x+4=x(x-1)/x(x-2)²