若|x+y-3|+(x-y+5)²,则xy=
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若|x+y-3|+(x-y+5)²,则xy=若|x+y-3|+(x-y+5)²,则xy=若|x+y-3|+(x-y+5)²,则xy=即/x+y-3/+(x-y+5)
若|x+y-3|+(x-y+5)²,则xy=
若|x+y-3|+(x-y+5)²,则xy=
若|x+y-3|+(x-y+5)²,则xy=
即
/x+y-3/+(x-y+5)²=0吧
∵/x+y-3/≥0
(x-y+5)²≥0
∴x+y-3=0
x-y+5=0
两式相加
∴x=-1,y=4
∴xy=-1×4=-4
x+y-3=0
x-y+5=0
x=-1
y=4
xy=-1*4=-4
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