1.(因式分解)m*m/9-mn/3+n*n/4.2.已知x*x+y*y-2x+1=0,求xy=________.3.已知x*x+4x+4+y*y-8y+16=0,求x/y的值

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1.(因式分解)m*m/9-mn/3+n*n/4.2.已知x*x+y*y-2x+1=0,求xy=________.3.已知x*x+4x+4+y*y-8y+16=0,求x/y的值

1.(因式分解)m*m/9-mn/3+n*n/4.2.已知x*x+y*y-2x+1=0,求xy=________.3.已知x*x+4x+4+y*y-8y+16=0,求x/y的值
1.(因式分解)m*m/9-mn/3+n*n/4.2.已知x*x+y*y-2x+1=0,求xy=________.
3.已知x*x+4x+4+y*y-8y+16=0,求x/y的值

1.(因式分解)m*m/9-mn/3+n*n/4.2.已知x*x+y*y-2x+1=0,求xy=________.3.已知x*x+4x+4+y*y-8y+16=0,求x/y的值
1、m*m/9-mn/3+n*n/4
原式=(m/3)²-2×(m/3)n/2+(n/2)²
=(m/3-n/2)²
.2.已知x*x+y*y-2x+1=0,求xy
∵x*x+y*y-2x+1=0
∴(X-1)²+Y²=0
∴X=1,Y=0
把X=1,Y=0代入xy=1×0=0
3.已知x*x+4x+4+y*y-8y+16=0,求x/y的值
∵x*x+4x+4+y*y-8y+16=0
∴(X+2)²+(Y-4)²=0
∴X+2=0,Y-4=0
∴X=-2,Y=4
把X=-2,Y=4代入x/y=-2/4=-1/2

m*m/9-mn/3+n*n/4=(m/3-n/2)(m/3-n/2)