分式加减 x²+3x-4分之2x - x-1分之x+1 +1快.
问题描述：
分式加减 x²+3x-4分之2x - x-1分之x+1 +1快.
答
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)...