整式乘法!已知x+y=6,x2-y2=48,求(x-y)2
已知:x2+4x+y2-6y+13=0,求(x-2y)/(x²+y²)
已知x,y为实数,且(x2 +y2)(x2 +y2+2)=3.求x2 +y2的值
已知实数x.y满足(x2+y2)(x2+y2-1)=2,求x2+y2的值
已知x2+y2=20,x2+xy-2y2=2(x+2y),求x+y的值
已知实数x,y满足x2+y2-2x+2y=6求x2+y2的最值
已知x,y满足x2+y2-6x-2y+5=0,求x2+y2的最大值
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+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x2+y2+4x-6y+13=0 求x2-2x\x2+3y2
已知x2-2x+y2+6y+10=0,求(2x-y)的值
已知:x2+2x+y2-6y+10=0,求x,y的值.