若|x+y-7|+(xy-3)²=0,则4x²+4y²的值为( )填空若|x+y-7|+(xy-3)²=0,则4x²+4y²的值为 ( )填空
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若|x+y-7|+(xy-3)²=0,则4x²+4y²的值为()填空若|x+y-7|+(xy-3)²=0,则4x²+4y²的值为()填空若|
若|x+y-7|+(xy-3)²=0,则4x²+4y²的值为( )填空若|x+y-7|+(xy-3)²=0,则4x²+4y²的值为 ( )填空
若|x+y-7|+(xy-3)²=0,则4x²+4y²的值为( )填空
若|x+y-7|+(xy-3)²=0,则4x²+4y²的值为 ( )填空
若|x+y-7|+(xy-3)²=0,则4x²+4y²的值为( )填空若|x+y-7|+(xy-3)²=0,则4x²+4y²的值为 ( )填空
|x+y-7|+(xy-3)²=0
所以x+y-7=0
xy-3=0
所以 xy=3
x+y=7
两边平方
x²+2xy+y²=49
所以x²+y²
=49-2xy
=49-6
=43
所以原式=4(x²+y²)
=4×43
=172