5x²y-[2x²y-3(xy²-2x²y+2xy²)],其中x,y满足丨x-1丨+（y+2）²=0

5x²y-[2x²y-3(xy²-2x²y+2xy²)],其中x,y满足丨x-1丨+（y+2）²=0

丨x-1丨+（y+2）²=0
∴x-1=0
y+2=0
∴x=1
y=-2
5x²y-[2x²y-3(xy²-2x²y+2xy²)]
=5x²y-2x²y+3xy²-6x²y+6xy²
=-3x²y+9xy²
=6+36
=42

丨x-1丨+（y+2）²=0
丨x-1丨=0,（y+2）²=0
x=1
y=-2
5x²y-[2x²y-3(xy²-2x²y+2xy²)]
=5x²y-[2x²y-3(3xy²-2x²y)]
=5x²y-[2x²y-9xy...

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丨x-1丨+（y+2）²=0
丨x-1丨=0,（y+2）²=0
x=1
y=-2
5x²y-[2x²y-3(xy²-2x²y+2xy²)]
=5x²y-[2x²y-3(3xy²-2x²y)]
=5x²y-[2x²y-9xy²+6x²y]
=5x²y-[2x²y+6x²y-9xy²]
=5x²y-[8x²y-9xy²]
=5x²y-8x²y+9xy²
=-3x²y+9xy²
=-3xy(x-3y)
=-3*1*(-2)*[1-3*(-2)]
=6*(1+6)
=6*7
=42

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