Question

x+1分之1减x的平方-1分之x+3乘以x的平方+4x+3分之x的平方-2x+1

Answer 1

首先计算(x+3)/(x^2-1) 乘以（x^2-2x+1）/(x^2+4x+3),分解因式可以得到(x+3)/(x+1)(x-1) 乘以

(x-1)^2/(x+3)(x+1),约分后等于(x-1)/(x+1)^2,然后1/(x+1)减去(x-1)/(x+1)^2最后等于2/(x+1)^2