分式加减 x²+3x-4分之2x - x-1分之x+1 +1快.

分式加减 x²+3x-4分之2x - x-1分之x+1 +1快.
分式加减 x²+3x-4分之2x - x-1分之x+1 +1快.

分式加减 x²+3x-4分之2x - x-1分之x+1 +1快.
原式=2x/(x²+3x-4)-(x+1)/(x-1)+1
=2x/[(x-1)(x+4)]-(x+1)(x+4)/[(x-1)(x+4)]+(x-1)(x+4)/[(x-1)(x+4)]
=[2x-(x+1)(x+4)+(x-1)(x+4)]/[(x-1)(x+4)]
=(2x-x²-5x-4+x²+3x-4)/[(x-1)(x+4)]
= -8/[(x-1)(x+4)]

神马才看得懂的式子