问题标题:
先化简,后计算!(写过程)(m²+3m)(m-3)-m(m-2)²,其中m=-2
问题描述:
先化简,后计算!(写过程)
(m²+3m)(m-3)-m(m-2)²,其中m=-2
陈忠明回答:
(m²+3m)(m-3)-m(m-2)²
=m(m+3)(m-3)-m(m²-2m+4)
=m(m²-9)-m(m²-4m+4)
=m(m²-9-m²+4m-4)
=m(4m-13)
=-2*[2*(-2)-13]
=-2*[-4-13]
=-2*(-17)
=34
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