计算: (1)-a×(-a)2×(-a)3=______; (2)(-a3)2=______; (3)(3x3y)2=______; (4)(-a)3÷a2=______ (5)x3y2×(-6x2y)=______; (6)(-3a2+b2-1)×(1-2a)=______; (7)(a-5)(5+a)=______; (8)(x+6)(x-2)=______; (9)(a+3b)2=______; (10)(2x-y)2=______; (11)(-4a3+12a4b-7a4b2)÷(-4a3)=______. |