已知y\x=3\4求3x^2-5xy+2Y^2 \2X^2+3XY-5Y^2

来源：学生作业帮编辑：神马作文网作业帮分类：数学作业时间：2024/11/12 05:09:30

$已知y\x=3\4求3x^2-5xy+2Y^2 \2X^2+3XY-5Y^2$

因为y\x=3\4
可设y=3k,x=4k
3x^2-5xy+2Y^2 \2X^2+3XY-5Y^2
=(3*16k^2-60k^2+2*9k^2)/(32k^2+3*12k^2-5*9k^2)
=(6k^2)/(23k^2)
=6/23

已知xy/x+y=3,求代数式2x-5xy+2y/x-3xy+y 已知xy/x+y=2,求代数式3x-5xy+3y/-x+2xy-y的值已知X+Y分之XY=2,求-X+3XY-Y分之3X+5XY+3Y 已知x-y=2xy,求代数式3x-5xy-3y/x+xy-y的值已知xy=2(x+y),求(5x-xy+5y)/(3xy-x-y)的值已知x,y>0 2x+y+3=xy 求5x+4y最小值已知xy^2=-2,求-xy（x^2y^5-xy^3-y)的值. 已知xy^2=-2 求-xy(x^2y^5-xy^3-y) 已知x+y=5,xy=2,求5x+4y-3y-2y+xy的值已知x^2-xy=5,xy-y^2=-3求3(x^2-xy)-xy+y^2 已知xy/(x+y)=2求(3x-5y+3y)/(-x+3xy-y) 已知xy/x+y=2,求代数式3x-5y+3y/-x+3xy-y