2x-3y=10,3x+7y=24

若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 2(x+y) 3x+3y=24 x+y/2x x y/2y= 1 { x-y/7-x+y/10=1/2 {2(x-y)+5(x+y)=3 已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 联立方程 1.{3X+7Y=15 2X-5Y=-19 24X-3Y=0 2X+Y=10 9X+10Y=-2 6X+Y+4 已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y 先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y 2X+Y+Z=10,X+2Y+Z=-6,X+Y+2Z=8 5X+4Y-3Y=13,2X-3Y+7Z=19,3X-Y=2X (3x-y)^2+(3x+y)(3x-y),x=1,y=-2