写清楚点
是证明2x+3是
2(x^4)-5(x^3)-10(x^2)+15x+18的因式吗?
补充：2(x^4)-5(x^3)-10(x^2)+15x+18
=[2(x^4)+3(x^3)]-[8(x^3)+12(x^2)]+[2(x^2)+3x]+(12x+18)
=x^3*(2x+3)-4(x^2)*(2x+3)+x*(2x+3)+6(2x+3)
=(2x+3)[x^3-4(x^2)+x+6]