1.若-y=-2,则y+2=X,求X的值2.已知一个数的相反数恰好比这个数的3倍少一,求此数

若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x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-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 y=3(x-y),x=2(x-y)求x,y的值 已知x≠y,x^2-x=y^2-y,求x+y的值. 若x*x+y*y=x+y-1/2,求x,y的值如题 x,y 满足x(x-2)-y(y-6)=-10,求x,y的值 正数x,y满足x-y=2xy,求x-y/x+y的值. 若(x+y)(x+y-1)-2=0,求x+y的值求 已知x+y=a,2x-y=-2a,求[（x/y-y/x)/(x+y)-x(1/x-1/y)]/[(x+1)/y]的值 若|x+y-1|+（x-y-2)²=0,求代数式（x+2y)(x-2y）-（2x-y)(-y-2x)的值. 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 x*x+2x-y*y+6y-8=0,x+y不等于2,求x-y的值 已知2/x+2/y=根号24,求 x/y(x-y) - y/x(x-y)的值 已知2/x 2/y=根号24,求 x/y(x-y) - y/x(x-y)的值 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?