已知x+y=6,xy=2,求下列个式的值:(1)x2+y2 (2)(x-y)2
已知x+y=6,xy=2,求下列个式的值:(1)x2+y2 (2)(x-y)2
已知x-y+1,X2+Y2=25 求(x+y)2和x2-xy+y2的值
已知2x=3y,求xy/(x2+y2)-y2/(x2-y2)的值
已知X2-2x+y2+6y+10=0,求(x2-2xy)/(xy+y2)的值
已知x2+y2=20,x2+xy-2y2=2(x+2y),求x+y的值
已知x(x-1)-(x2-y)=-3,求x2+y2-2xy的值
已知x2+y2-10x-6y+34=0,求(x-y/x+y)2÷x2-y2/xy×x2+2xy+y2/x2-xy 的值.
已知X2+Y2+8X+6Y+25=0 求代数式X2++XY+4Y2分之X2-4Y2 减X+2Y分之X的值
已知实数x,y满足(x2)+(y2)-xy+2x-y+1=0,求x,y的值
已知实数x、y满足X2+y2-xy+2x-y+1=0,试求x、y的值
已知x+y=8,xy=12,求x2+y2;(x-y)2的值
x(x-1)-(x2-y)=-3,求x2+y2-2xy的值