3ab{2ab+3(ab-0.5a的2次方b)}

网友回答

∵(a+2)^2恒≥0 ,|3b-1|恒≥0
∴a=-2 ,b=1/3
3a^2b - [2ab^2 - 6(ab - 0.5a^2b) + 4ab] - 2ab
=3a^2b - (2ab^2 - 6ab + 3a^2b + 4ab) - 2ab
=3a^2b - 2ab^2 + 6ab - 3a^2b - 4ab - 2ab
=-2ab^2
=(-2)×(-2)×(1/3)^2
=4/9