Question

求解以下数学问题！！！

2x/x^2-1 - 2-x/1-x

x/x^2-9 +1/3-x -2/3+x

Thanks~

Answer 1

按常理算，第一题应该x^2-1应该加括号 计算如下
2x/(x^2-1)-2-x/1-x=2x/(x+1)(x-1)-2-x/1-x=2x/(x+1)(x-1)-2x(1+x)/(1-x)(1+x)
2x/(x+1)(x-1)+2x(1+x)/(1+x)(x-1)=2x(x+2)/x^2-1

第二题：x/(x^2-9)+(3+x)/(3-x)(3+x)-2(x-3)/(3+x)(x-3)
=x/(x^2-9)-(3+x)/(x^2-9)-2(x-3)/(x^2-9)
=(x-3-x-2x+6)/(x^2-9)
=(3-2x)/(x^2-9)

Answer 2

(-x^2+3x+2)/(x^2-1)

(-2x+3)/(x^2-9)

Answer 3

从算