通分：x^2-6x+9分之x,2(3-x)分之1通分：x^2-4分之1,4-2x分之x

Question

通分：x^2 -6x+9分之x,2(3-x)分之1
通分：x^2 -4分之1,4-2x分之x

Answer 1

1、它们的最简公分母是2(x-3)²
x/(x²-6x+9)=x/(x-3)²=2x/2(x-3)²
1/2(3-x)=-1/2(x-3)=-(x-3)/2(x-3)²
2、最简公分母是2(x+2)(x-2)
1/(x²-4)=1/(x+2)(x-2)=2/2(x+2)(x-2)
x/(4-2x)=-x/2(x-2)=-x(x+2)/2(x+2)(x-2)