x^2+4x+2/x^2+4x+3-x^2+7x+5/x^2+7x+6
问题描述：
x^2+4x+2/x^2+4x+3-x^2+7x+5/x^2+7x+6
答
(x²+4x+2)/(x²+4x+3)-(x²+7x+5)/(x²+7x+6)
=(x²+4x+2)/(x+1)(x+3)-(x²+7x+5)/(x+1)(x+6)
=[(x+6)(x²+4x+2)-(x+3)(x²+7x+5)]/(x+1)(x+3)(x+6)
=[x³+4x²+2x+6x²+24x+12-(x³+7x²+5x+3x²+21x+15)]/(x+1)(x+3)(x+6)
=-3/(x+1)(x+3)(x+6)7/x^2+3x+2-4/x^2+4x+3+2/x^2+5x+6谢啦~~原式=(7-4+2)/x²+(3+4+5)x+2+3+6 =5/x²+12x+11