计算.a^2-[-4ab+(ab-a^2)]-2ab

问题描述:

计算.a^2-[-4ab+(ab-a^2)]-2ab

=a^2-(-3ab-a^2)-2ab
=a^2+3ab+a^2-2ab
=a^2+a^2+3ab-2ab
=2a^2+ab