题目内容
( )(-4a2)=12a4-16a3+4a2.
-3a2+4a-1
(1)4x(a-B)+(B2-a2); (2)(a2+B2)2-4a2B2;
(3)x4+2x2-3; (4)(x+y)2-3(x+y)+2;
(5)x3-2x2-3x; (6)x3-3x2-4x+12;
(7)4a2-B2+6a-3B (8)2x3y+8x2y2+8xy3;