x^2+8x+13/x^2+8x+15-x^2+5

x^2+8x+13/x^2+8x+15-x^2+5x+4/x^2+5x+6

1个回答

原式=(x²+8x+13)/(x+3)(x+5)-(x²+5x+4)/(x+2)(x+3)
=(x³+10x²+29x+26-x³-10x²--29x-20)/(x+2)(x+3)(x+5)
=6*(x³+10x²+31x+30)