X/Y=2/5 X+60/Y=4/7 问X.Y各是多少

X/Y=2/5 X+60/Y=4/7 问X.Y各是多少 x－y=4 ｜x｜+｜y｜=7 问x、y的值为多少? 1.（X-Y）/13=Y/7问（x+y）/y=?.2.x/6=y/4=z/3(x.z.y不为0)则（X+3Y）/3Y-2Z=? 1.3x+4y=256x+5y=38问：x与y各是多少?2.条件：7z-3=2y-6=4y-16=3x-8[y*y-(x*x+z*z)/x*x+y*y+z*z]乘以7/3=? 问：2x-5y-4=0 求：x=?y=? 例X=1 y=21.X+Y=5 X-Y=15 2.2X+3Y=4 5X+6Y=7 3.X+3Y=5 3X+Y=-1 4.2X+Y=3 3X+5Y=11 5.4X+3Y=6 2X+Y=4 6.X+Y=180 X=3Y-10 7.3X-2Y=3 2X-Y=7 8.5X+3Y=7Y X+Y=45 9.3X+4Y=126X+8Y=24 X:6Y=1:4 10.X+Y=138 X-45=Y+53 11.X+Y=60 14Y=20X 12.2X+3Y=15.5 5X+6Y=35 13.X+Y=170 3 把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)= 3(x-y)把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)=3(x-y)²-4(x-y)+7(x-y)-6(x-y)²= 解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7 {6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1 x*x+2x+y*y-4y+5=0 x= y= 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 问一条数学题：已知实数x、y满足√(2x-3y-1) + |x-2y+2|=0,求2x- 4/5y的值 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 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 把(x-y)看做一个整体,合并同类项5(x-y)+2(x-y)-4(x-y)=3(x-y)次方-4(x-y)+7(x-y)-6(x-y)次方=