9x+2y=62.4x+3y=36.求x,y

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) 已知4x=9y求(1)x+y/y (2)y-x/2x 已知2x-y/x+2y=3,求2(2x-y)/x+2y-9(x+2y)/2x-y+3的值. 3x=2y+1;x=9y;求x,y的值? 已知x/y=3/2求代数式4x-9y/2x+3y 已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-( 已知：3x=8y.求（1）x+y/y (2)2x+3y/x-2y 已知x,y满足{3x-y=9 {x-3y=0 求x+2y+ 4y的平方/x-2y -4x的平方y/x的平方-4y的平方 y=2x*arctan(y/x),求y‘’ 已知xy=-2,x-y=3,求（x+y)（x-y)-y^2+（x-y)^2-（6x^2y-2xy^2)÷2y 已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)X(x-y)