题目内容
多项式-x2y+xy-x+1是________次________项式.
下列多项式分解因式结果正确的是
A.-x2+y2=(x+y)(y-x)
B.x2-2x-1=(x+1)(x-1)-2x
C.x2y+xy-xy2=xy(x-y)
D.x2-3x+9=(x-3)2
根据你学习多项式乘法的经验,你能找到下列各式的答案的正确序号吗?
(1)x2-y2=________; (2)ab-bc=________;
(3)xy2-x2y-xy=________; (4)4a2-4a+1=________;
(5)x2-2x-3=________; (6)4a2-m2________.
①(2a-1)2 ②(x+y)(x-y)
③(x-3)(x+1) ④b(a-c)
⑤ ⑥xy(y-x-1)