问题 填空题
______-2xy+4y2=(______)2;x2+
b
a
x+______=(______)2
答案

∵2y×

1
2
x=2xy,

1
4
x2-2xy+4y2=(
1
2
x-2y)2

∵x×

b
2a
=
b
a
x,

∴x2+

b
a
x+
b2
4a2
=(x+
b
2a
2

故答案为:

1
4
x2
1
2
x-2y,
b2
4a2
,x+
b
2a

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