2xy+y+x=83求x+y=多少?

x+y+2xy=83求x+y=? xy-[x+2y+0.5(x-4)*(y-2)]=24求x*y等于多少 2xy+y+x=83求x+y=多少? 分式正数x,y满足x平方-y平方=2xy,求x-y/x+y等于多少,快 1/x-1/y=3 求x-3xy-y/2x-xy-2y 等于多少 f(x+y,x-y)=(x^2-y^2)/2xy,求f(x,y)! 正数x,y满足x-y=2xy,求x-y/x+y的值. f(x+y,x-y)=2xy(x-y),求f(x,y) x^2+xy+x=36,y^2+xy+y=20,求x+y. 若x^2+xy+y=14,y^2+xy+x=28,求x+y 如果x^2+xy+y-14,y^@+xy+x=28,求x+y的值. f(xy,x-y)=x^2-xy+y^2.求f(x,y) 已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值? x^2-y^2=xy 求x/y, 若2x+y=6 xy=2.5 求2x—y等于多少 x→2,y→0,求lim sin[(8 -x)y]/xy=多少呀? 若1/x-1/y=2,求3x-2xy-3y/x-xy-y的值3x-2xy-3y/x-xy-y 不好意思，是3x-2xy-3y/x-2xy-y x+y分之一=5,xy+xy分之一=18,求y+x分之一=多少