x^2+2x-3/x^3+7x^2+7x-15
问题描述:
x^2+2x-3/x^3+7x^2+7x-15
答
因为:x^2+2x-3=(x+3)(x-1)
x^3+7x^2+7x-15=(x+5)(x+3)(x-1)
所以:原式=(x+3)(x-1)/(x+5)(x+3)(x-1)
=1/(x+5)