已知|x+2y+1|+(-y-2)²=0,求(2x-y)²-2(2x-y)(x+2y)²
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已知|x+2y+1|+(-y-2)²=0,求(2x-y)²-2(2x-y)(x+2y)²
已知|x+2y+1|+(-y-2)²=0,求(2x-y)²-2(2x-y)(x+2y)²
已知|x+2y+1|+(-y-2)²=0,求(2x-y)²-2(2x-y)(x+2y)²
|x+2y+1|+(-y-2)²=0
∴x+2y+1=0
-y-2=0
∴x=3
y=-2
(2x-y)²-2(2x-y)(x+2y)²
=(6+2)²-2(6+2)(3-4)²
=64-16
=48
绝对值和平方数都是非负数,和为0的话 只能他们都等于0
(-y-2)²=0 y=-2
|x+2y+1|=0 x =3
原式=64 - 2 X 8 X 1 = 48
x+2y=-1
y=-2
x=3
2x-y=8
原式=64-2*8*1
=48