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第48页

信息发布者：

$4x^2+4xy+y^2$

$16-24a+9a^2$

-b

x-4y

$16y^2$

100

$100^2-2×100×2+2^2$

9604

100

$100^2+2×100×1+1^2$

10201

1或-1

$=x^2-4xy+4y^2-x^2+4xy$

$=4y^2$

$=\frac {1}{4}x²-2×\frac {1}{2}x×\frac {5}{3}y+(\frac {5}{3}y)²$

$=\frac {1}{4}x²-\frac {5}{3}xy+\frac {25}{9}y²$

$=-(2a+7b)²$

$=-4a²-28ab-49b²$

$=9{x}^{2n+2}+2×(-3×\frac {1}{3}){x}^{n+1}{y}^{n-1}+\frac {1}{9}{y}^{2n-2}$

$=9{x}^{2n+2}-2{x}^{n+1}{y}^{n-1}+\frac {1}{9}{y}^{2n-2}$