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化简求值,若X方-2XY+Y方+1XY-11=0,求X方+6XY+9Y方分之X方-25Y方*5X-25Y分之X+3Y的值

题目详情
化简求值,若X方-2XY+Y方+1XY-11=0,求X方+6XY+9Y方分之X方-25Y方*5X-25Y分之X+3Y的值
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答案和解析
若X方-2XY+Y方+1XY-11=0
则:x-y=0.而且xy=1
所以,x=y=1,或者,x=y=-1
所以,x/y=1
X方+6XY+9Y方分之X方-25Y方*5X-25Y分之X+3Y
=(x²-25y²)/(x+3y)² ·(x+3y)/5(x-5y)
=(x+5y)(x-5y)/(x+3y)² ·(x+3y)/5(x-5y)
=(x+5y)/(x+3y)
=【(x/y)+5】【(x/y)+3】
=(1+5)/(1+3)
=1.5