已知x=3/2,求x(x²-x)+x²(5-x)-9的值

来源：学生作业学帮网编辑：学帮网时间：2024/06/06 19:18:50

x(x²-x)+x²(5-x)-9
=x³-x²+5x²-x³-9
=4x²-9
=4x(3/2)²-9
=4x9/4-9
=9-9
=0

x(x²-x)+x²(5-x)-9
=x³-x²+5x²-x³-9
=4x²-9
=(2x+3)(2x-3)
=(2×3/2+3)(2×3/2-3)
=6×0
=0