2/5X+4/9Y=180,请问X.Y各等于多少题目是这样的,X.Y.Z共有180元,X是Y+Z和的1/5,Y是X+Z和的2/9,问各有多少钱?

4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值 请问 0=-5x+y-1 与 1=4x-3y+2 x*y的值是多少 3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 x*x+2x+y*y-4y+5=0 x= y= 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 (x-y)/4+(x+y)/5=1/4 (x+y)/9-(x-y)/3=//2(x-y)/4+(x+y)/5=1/4(x+y)/9-(x-y)/3=//2 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 接二元一次4(x+y)-3(x-y)=9;5(x-y)+2(x+y)=11 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值 请问方程 2x-5y=4与3x+2y=6 X/Y=2/5 X+60/Y=4/7 问X.Y各是多少 x+y=5 2x+3y-z=9 x-y+z=4 已知x*x+4x+y*y-2y+5=0,则x*x+y*y=? 2/5X+4/9Y=180,请问X.Y各等于多少题目是这样的,X.Y.Z共有180元,X是Y+Z和的1/5,Y是X+Z和的2/9,问各有多少钱? 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2