X2+2XY+y2+x+y
已知2x=3y,求xy/(x2+y2)-y2/(x2-y2)的值
x2-xy-2y2-x+5y-2
x2-2xy+y2+3x-3y+2.
x2-xy-2y2-x+5y-2因式分解
因式分解 x2+xy-2y2-x+7y-6
2x2+xy-3y2+x+4y-1因式分解
25(x2+ 2xy +y2)-9(x2-2xy+y2)因式分解.x2,y2是x平方,y平方的意思.2xy就是2xy.快
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
已知x2+4y2+x2y2-6xy+1=0,求 x4-y4/2x-y 乘 2xy-y2/xy-y2 除以(x2+y2/x
正数xy满足x2-y2=2xy,求x+y分之x-y的值
若x<y<0,则x2−2xy+y2+x2+2xy+y2=( )