若X\2=Y\3,则分式(7X²―y²)\(X²―2XY+3y²)的值是多少?
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![若X\2=Y\3,则分式(7X²―y²)\(X²―2XY+3y²)的值是多少?](/uploads/image/z/980004-12-4.jpg?t=%E8%8B%A5X%5C2%3DY%5C3%2C%E5%88%99%E5%88%86%E5%BC%8F%287X%26sup2%3B%E2%80%95y%26sup2%3B%29%5C%28X%26sup2%3B%E2%80%952XY%2B3y%26sup2%3B%29%E7%9A%84%E5%80%BC%E6%98%AF%E5%A4%9A%E5%B0%91%3F)
若X\2=Y\3,则分式(7X²―y²)\(X²―2XY+3y²)的值是多少?
若X\2=Y\3,则分式(7X²―y²)\(X²―2XY+3y²)的值是多少?
若X\2=Y\3,则分式(7X²―y²)\(X²―2XY+3y²)的值是多少?
令k=X\2=Y\3
则X=2k,Y=3k
所以(7X²―y²)\(X²―2XY+3y²)
=(28k²-9k²)/(4k²-12k²+27k²)
=19k²/(19k²)
=1
X\2=Y\3
x=2y/3
(7X²―y²)\(X²―2XY+3y²)
=(28y^2/9-y^2)/(4y^2/9-4y^2/3+3y^2)
=(19y^2/9) / (19y^2/9)
=1