如果x:y=2:3,求x^2+xy+2y^2/x^2-xy+y^2的值

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如果x:y=2:3,求x^2+xy+2y^2/x^2-xy+y^2的值如果x:y=2:3,求x^2+xy+2y^2/x^2-xy+y^2的值如果x:y=2:3,求x^2+xy+2y^2/x^2-xy+

如果x:y=2:3,求x^2+xy+2y^2/x^2-xy+y^2的值
如果x:y=2:3,求x^2+xy+2y^2/x^2-xy+y^2的值

如果x:y=2:3,求x^2+xy+2y^2/x^2-xy+y^2的值
(x²+xy+2y²)/(x²-xy+y²)=[(x/y)²+(x/y)+1]/[(x/y)²-(x/y)+1]=[(2/3)²+(2/3)+1]/[(2/3)²-(2/3)+1]=19/7;

根据比例,可设x=2,y=3
则有:x^2=4,y^2=9,xy=6
所以所求的式子=(4+6+2*9)/(4-6+9)=28/7=4.