(x2+y2)(x2-y2)化简
直线x2+y2
(2x2-3xy+4y2)+(x2+2xy-3y2)化简(要有过程)
分解因式(1) x2+y2 (2) -x2-y2
X2+3xy+y2因式分解
x2-y2=xy,xy不等于0求x2/y2=y2/x2
已知(x2+y2+3)(x2+y2-2)-6=0,求x2+y2的值
已知2x=3y,求xy/(x2+y2)-y2/(x2-y2)的值
2010.09.已知x、y为实数,且(x2+y2)(x2+y2+1)=20,求x2+y2的值
已知(x2+y2)(x2+y2-6)+9=0,求x2+y2的值.
已知(x2+y2)(x2-1+y2)-12=0,求x2+y2的值.
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