3（a^2-2ab)-2(-3ab-b^2)3a^2-[a^2+(4a^2-2a)-2(a^2-3a_]_数学解答

3（a^2-2ab)-2(-3ab-b^2)
3a^2-[a^2+(4a^2-2a)-2(a^2-3a_]

人气：461 ℃　时间：2020-03-28 10:14:53

解答

3（a²-2ab)-2(-3ab-b²) =3a²-6ab+6ab+2b² =3a²+2b² 3a²-[a²+(4a²-2a)-2(a²-3a_] =3a²-[a²+4a²-2a-2a²+6a] =3a²-a²-4a²+2a+2...