1.已知a+b=-2,ab=3,则2[ab+(-3a)]-3[2b-ab]等于多少?

1.已知a+b=-2,ab=3,则2[ab+(-3a)]-3[2b-ab]等于多少
2[ab+(-3a)]-3[2b-ab]
=2ab-6a-6b+3ab
=5ab-6(a+b)
=15+12
=27
1.已知-3a的m次方bc的二次方与6a的三次方b的N次方c是同类项,求式子3m的二次方n-[2mn的二次方-3（-m的二次方n+mn的二次方）]的值
m+1+2=3+n+1
m=n+1
3m的二次方n-[2mn的二次方-3（-m的二次方n+mn的二次方）]
=3m²n-2mn²-3m²n+3mn²
=mn²