几道数学计算题.化简.
-2a^2(1/2AB+b^2)+2A(a^2b-ab^2)
(9x^2+2)(2X+1)
(X+2)^2-(X+1)(X-3)
-2(-a^2bc)^2*1/2a(bc)^3-(-abc)^3(-abc)^3