问题标题:
3x3-【x3+(6x2-7x)-2(x3-3xy-4y)],其中x=-1,y=1求值.
更新时间:2024-04-29 14:37:20
问题描述:
3x3-【x3+(6x2-7x)-2(x3-3xy-4y)],其中x=-1,y=1求值.
郝建标回答:
3x3-【x3+(6x2-7x)-2(x3-3xy-4y)]
=3x3-x3-(6x2-7x)+2(x3-3xy-4y)
=2x3-6x2+7x+2x3-6xy-8y
=4x3-6x2-6xy-y
=-4-6+6-1
=-5
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