计算①:2[a(b-3)-b(a-3)+3(a-b)] ②:2ab[3ab-4(0.5ab-1.5a²b)+2ab(2 -3a)

问题描述:

计算①:2[a(b-3)-b(a-3)+3(a-b)] ②:2ab[3ab-4(0.5ab-1.5a²b)+2ab(2 -3a)