(a^2-1)*[2a^2-3a+5/a^2-1 -(2a/1-a) - 4/1+a]

问题描述:

(a^2-1)*[2a^2-3a+5/a^2-1 -(2a/1-a) - 4/1+a]
写错了。是(a^2-1)*[2a^2-3a+5/a^2-1 -(1-2a/1-a) - 4/1+a]

(a^2-1)*[2a^2-3a+5/a^2-1 -(2a/1-a) - 4/1+a] =(a^2-1)*[(2a^2-3a+5)/(a^2-1) -(1-2a/(1-a) - 4/(1+a)] =(a^2-1)*(2a^2-3a+5)/(a^2-1) -(a^2-1)*(1-2a)/(1-a) - (a^2-1)*4/(1+a)=(2a^2-3a+5) -(a-1)(a+1)*(1-2a)/(1...