题目有错吧 应是：X^4+X^3–5X+3 原式=X^4-X^3+2X^3–2X²+2x²-2x-3x+3 =x³(x-1)+2x²(x-1)+2x(x-1)-3(x-1) =（x-1）(x³+2x²+2x-3)
