通分:(x-1)(x-2)分之1,x的平方-2x+1分之2

问题描述:

通分:(x-1)(x-2)分之1,x的平方-2x+1分之2

1/(x-1)(x-2)=(x-1)/[(x-2)(x-1)^2]
2/(x^2-2x+1)=2/(x-1)^2=2(x-2)/[(x-2)(x-1)^2]

若中间为加号1/[(x-1)(x-2)]+2/(x^2-2x+1)=(x-1)/[(x-1)^2(x-2)]+2(x-2)/[(x-1)^2(x-2)]
=[(x-1)+2(x-2)]/[(x-1)^2(x-2)]=(3x-5)/[(x-1)^2(x-2)]
若中间为减号1/[(x-1)(x-2)]-2/(x^2-2x+1)=(x-1)/[(x-1)^2(x-2)]-2(x-2)/[(x-1)^2(x-2)]
=[(x-1)-2(x-2)]/[(x-1)^2(x-2)]=(-x+3)/[(x-1)^2(x-2)]