求解初二数学题
=1/[(x-3)(x+1) +1/[(x+1)(x-1)] +1/[(x+6)(x-3)]
=[(x-1)(x+6)+(x-3)(x+6)+(x+1)(x-1)] / [(x-3)(x+1)(x-1)(x+6)]
=(x²+5x-6+x²+3x-18+x²-1) /[(x-3)(x+1)(x-1)(x+6)]
=(3x²+8x-25) / [(x-3)(x+1)(x-1)(x+6)]