x+y=138,3x+5y=540 求x y的值

已知:3x-5y=0,求x/y,x-y/y,x-y/x x+y=138,3x+5y=540 求x y的值 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) {(x+y)/2+(x-y)/3=1,(x+y)-5(x-y)=2.求x=?,y=? |x|=3 |y|=5 |x-y|=|x|+|y| 求 X+Y和 X-Y 等于多少 （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 用递归法求y=x-(x*x*x/3!)+(x*x*x*x*x/5!)-(x*x*x*x*x*x*x/7!)+. 5X+Y=3 X+5Y=2 求x和y.5X+Y=3X+5Y=2求x和y. 已知x.x+y.y-6x-8y+25=0,求3x.x+5y的值 已知3x =2y 求x/x+y+y/x-y-y²/x²-y² 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 6X+3Y=5(X+Y)求结果 3x+5y=45 求x.y 已知：x*x+√3y=√5,y*y+√3x=√5,且x≠y,求 y/x+x/y 若x-y/x+y=5,求x-y/2x+2y+5x+5y/3x-3y的值 若x+y分之x-y=3,求式子x+y分之5(x-y)—2(x-y)分之x+y的值 若x-y分之x+y=3,求式子x+y分之5(x-y)—2（x-y）分之x+y的值