5x+11y=37求x+y

5x+11y=37求x+y 已知:3x-5y=0,求x/y,x-y/y,x-y/x 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 求(X+Y)(X-Y)(X²+Y²),X=5 Y=2, (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) 若x,y是正整数,且满足x(x+y)-y(x+y)=11求x+y的值 若x、y为正整数,且满足x(x+y)-y(x+y)=11,求x,y的值 {(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 已知x+y=-5,x*x+y*y=19求xy和（x-y)*(x-y)的值 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=2,y=3,求代数式（x-y）*（x-y）^3*(x-y)^5*……*(x-y)^11 已知x+y/y=11/8,求x-y/x+2y的值. 1/x-1/y=x,求5y+xy-5y/y-xy-x=? 已知5x-4y=0,求x:y和x+y:y的值 二元函数f(x,y)=x+y/x-y,求f(y/x,x/y) 求y'=y/(y-x)