-1-乘法公式1.填空:(1)221111()9423abba();(2)(4m22)168(mm);(3)2222(2)4(abcabc).2.选择题:(1)若212xmxk是一个完全平方式,则k等于()(A)2m(B)214m(C)213m(D)2116m(2)不论a,b为何实数,22248abab的值()(A)总是正数(B)总是负数(C)可以是零(D)可以是正数也可以是负数因式分解一、填空题:1、把下列各式分解因式:(1)652xx__________________________________________________
(2)652xx__________________________________________________
(3)652xx__________________________________________________
(4)652xx__________________________________________________
(5)axax12__________________________________________________
(6)18112xx__________________________________________________
(7)2762xx__________________________________________________
(8)91242mm__________________________________________________
(9)2675xx__________________________________________________
(10)22612yxyx____________________________________