十字相乘法
问题描述:
十字相乘法
化简:5/(x²-3x-4) + 4/(x²-5x-6) - 8/(x²-10x+24)
答
5/(x²-3x-4) +4/(x²-5x-6) -8/(x²-10x+24)=5/[(x+1)(x-4)]+4/[(x+1)(x-6)]-8/[(x-6)(x-4)]=[5(x-6)+4(x-4)-8(x+1)]/[(x+1)(x-4)(x-6)]=(5x-30+4x-16-8x-8)/[(x+1)(x-4)(x-6)]=(x-54)/[(x+1)(x-...