已知a+b=-3,ab=4,求2[ab+(-3a)]-3(2b-ab)的值写好每一步!

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已知a+b=-3,ab=4,求2[ab+(-3a)]-3(2b-ab)的值写好每一步!
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已知a+b=-3,ab=4,求2[ab+(-3a)]-3(2b-ab)的值写好每一步!
已知a+b=-3,ab=4,求2[ab+(-3a)]-3(2b-ab)的值
写好每一步!

已知a+b=-3,ab=4,求2[ab+(-3a)]-3(2b-ab)的值写好每一步!
2[ab+(-3a)]-3(2b-ab)
=2ab-6a-6b+3ab
=5ab-6(a+b)
=5×4-6×(-3)
=20+18
=38

2[ab+(-3a)]-3(2b-ab)
=2(ab-3a)-3(2b-ab)
=2ab-6a-6b+3ab
=5ab-6(a+b)
=5*4-6*(-3)
=20+18
=38