完全平方式.docx

1、口答：（抢答形式，活跃课堂气氛，激发学生的学习积极性）
   (m+n)2=____________, (m-n)2=_______________,
   (-m+n)2=____________, (-m-n)2=______________,
   (a+3)2=______________, (-c+5)2=______________,
   (-7-a)2=______________, (0.5-a)2=______________.
2、判断：
    (    )① (a-2b)2= a2-2ab+b2
    (    )② (2m+n)2= 2m2+4mn+n2
(    )③ (-n-3m)2= n2-6mn+9m2
(    )④ (5a+0.2b)2= 25a2+5ab+0.4b2
(    )⑤ (5a-0.2b)2= 5a2-5ab+0.04b2
(    )⑥ (-a-2b)2=(a+2b)2
(    )⑦ (2a-4b)2=(4a-2b)2
(    )⑧ (-5m+n)2=(-n+5m)2
3、小试牛刀
① (x+y)2 =______________;② (-y-x)2 =_______________;
③ (2x+3)2 =_____________;④ (3a-2)2 =_______________;
⑤ (2x+3y)2 =____________;⑥ (4x-5y)2 =______________;
⑦ (0.5m+n)2 =___________;⑧ (a-0.6b)2 =_____________.