初一分式加减1.2/(x-1)-(x+1)/(x-1)2.2a/(a^-4）-1/（a-2）3.3x/(x-3)^2+x/(x-3)4.【2a/(x-2)-x(x+2)】*(x^2-4)/x
问题描述：
初一分式加减
1.2/(x-1)-(x+1)/(x-1)
2.2a/(a^-4）-1/（a-2）
3.3x/(x-3)^2+x/(x-3)
4.【2a/(x-2)-x(x+2)】*(x^2-4)/x
答
1.=2-x-1/x-1=1-x/x-1=-1(提个负号）
2.不会
3.=3x/(x-3)^2+x^2-3x/(x-3)^2=x^2/(x-3)^2
4.看不懂
sorry
答
1.2/(x-1)-(x+1)/(x-1)=[2-(x+1)]/(x-1)=(-x+1)/(x-1)=-(x-1)/(x-1)=-12.2a/(a^2-4）-1/（a-2）=2a/(a+2)(a-2)-(a+2)/(a+2)(a-2)=(2a-a-2)/(a+2)(a-2)=(a-2)/(a+2)(a-2)=1/(a+2)3.3x/(x-3)^2+x/(x-3)=3x/(x-3)^2+x(x...