3a(a^2b-3b^3-2)-2b(2a^3-5b^2+1)
问题描述：
3a(a^2b-3b^3-2)-2b(2a^3-5b^2+1)
答
3a(a^2b-3b^3-2)-2b(2a^3-5b^2+1)
=3a^3b-9ab^3-6a-(4a^3b-10b^3+2b)
=3a^3b-9ab^3-6a-4a^3b+10b^3-2b
=3a^3b-4a^3b-9ab^3+10b^3-6a-2b
=-a^3b-9ab^3+10b^3-6a-2b