x+y=14 5x+4y=60 求"x”的解

已知：4x = 5y,求(x+y) ：y 已知:3x-5y=0,求x/y,x-y/y,x-y/x x+y=14 5x+4y=60 求x”的解 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 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 若(-x+6):(x-y):(4x+y)=3:14:1,求x+y 若(-x+6):(x-y):(4x+y)=3:14:1,求x+y (-x+6):(x-y);(4x+y)=3;14:1,求x+y的值. x*x+y*y-2x+4y+5=0求x, 已知5x-4y=0,求x:y和x+y:y的值 已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值 x+x+x+y=60 .x-y=4 如果|X|=4 |Y|=2 且|X+Y|=X+Y 求X+Y 求(X+Y)(X-Y)(X²+Y²),X=5 Y=2, (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) x(x-3y)=4y(x-3y),求x:y x/3=y/4,求(x*x-xy)/(x*x+y*y)的值 5x-4y(y-x)=?