若x2+y2=3,x-y=2,求xy的值和x+y的值,(x2是x的平方)
已知2x=3y,求xy/(x2+y2)-y2/(x2-y2)的值
已知x-y+1,X2+Y2=25 求(x+y)2和x2-xy+y2的值
x(x-1)-(x2-y)=-3,求x2+y2-2xy的值
若X2+Y2-2X-6Y+10=0 ,求(x2-y2)/xy的值
已知:x=3,y=-5,x2-2xy+y2/x2-y2的值是
x(x-1)-(x2-y)=-3,求x2-y2-2xy的值
已知x(x-1)-(x2-y)=-3,求x2+y2-2xy的值
已知x2+y2=20,x2+xy-2y2=2(x+2y),求x+y的值
正整数x,y满足x2-y2=2xy,求x-y/x+y的值
整数x,y满足x2-y2=2xy,求x-y/x+y的值
X2-4XY+3Y2=0(跟在字母后面的2是平方),且XY不等于零,求X/Y+Y/X的值
已知(x+y)2=25,xy=3,求x2+y2求x2+y2的值答案是?