(1)1-x分之x-x-3分之1 （2）1-x乘以1-x分之1 （3)2x-3分之3+3-2x分之1+2x+4x^2-9

(1)1-x分之x-x-3分之1
=x/(1-x)-1/(x-3)
=[x(x-3)-(1-x)]/(1-x)(x-3)
=(x²-3x-1+x)/(1-x)(x-3)
=(x²-2x-1)/(-3-2x-x²)
（2）1-x乘以1-x分之1
=(1-x)*1/(1-x)
=1
（3)2x-3分之3+3-2x分之1+2x+4x^2-9分之2x+3
=3/(2x-3)+(1+2x)/(3-2x)+(2x+3)/(2x-3)(2x+3)
=3/(2x-3)-(1+2x)/(2x-3)+1(2x-3)
=(3-1-2x+1)/(2x-3)
=(3-2x)/(2x-3)
=-1

(1)1-x分之x-x-3分之1
（2）1-x乘以1-x分之1 =1
（3)2x-3分之3+3-2x分之1+2x+4x^2-9分之2x+3
=3/(2x-3)+(1+2x)/(3-2x)+(2x+3)/(4x^2-9)具体过程等等 (1)1-x分之x-x-3分之1 =x/(1-x)-1/(x-3)(通分) =[x(x-3)-(1-x)]/(1-x)(x-3) =...

x/(1-x)-1/(x-3)
=-x(x-1)-1/(x-3)
=-(x-3)/[(x-1)(x-3)]-(x-1)/[(x-1)(x-3)]
=[-(x-3)-(x-1)]/[(x-1)(x-3)]
=[-x+3-x+1]/[(x-1)(x-3)]
=[-2x+4]/[(x-1)(x-3)]
=-2(x-2)/[(x-1)(x-3)]
1...