5x+11y=37求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 = 5y,求(x+y) ：y |x|=3 |y|=5 |x-y|=|x|+|y| 求 X+Y和 X-Y 等于多少 已知x+y=-5,x*x+y*y=19求xy和（x-y)*(x-y)的值 已知x=2,y=3,求代数式（x-y）*（x-y）^3*(x-y)^5*……*(x-y)^11 二元函数f(x,y)=x+y/x-y,求f(y/x,x/y) 已知x+y/y=11/8,求x-y/x+2y的值. 求y'=y/(y-x) 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x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y 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* 已知x+y/x=11/8,求x-y/x+2y的值