已知a+b=-2,ab=3,则2[ab+(-3a)]-3(2b-ab)=?
问题描述：
已知a+b=-2,ab=3,则2[ab+(-3a)]-3(2b-ab)=?
答
题不对
答
2[ab+(-3a)]-3(2b-ab)
=2ab-6a-6b+3ab
=5ab-6(a+b)
=5*3-6*(-2)
=15+12
=27