.(x^2+y^2)(x^2+y^2-2008)=2009,求x^2+y^2的值
来源：学生作业帮助网 编辑：六六作业网 时间：2024/12/23 06:38:17
.(x^2+y^2)(x^2+y^2-2008)=2009,求x^2+y^2的值.(x^2+y^2)(x^2+y^2-2008)=2009,求x^2+y^2的值.(x^2+y^2)(x^2+y^2-2
.(x^2+y^2)(x^2+y^2-2008)=2009,求x^2+y^2的值
.(x^2+y^2)(x^2+y^2-2008)=2009,求x^2+y^2的值
.(x^2+y^2)(x^2+y^2-2008)=2009,求x^2+y^2的值
(x^2+y^2)(x^2+y^2-2008)=2009,
(x^2+y^2)^2-2008(x^2+y^2)-2009=0,
(x^2+y^2-2009)((x^2+y^2+1)=0,
x^2+y^2=2009,x^2+y^2=-1(舍去)
所以x^2+y^2=2009
就是换元法。 设x^2+y^2=t
则 t(t-2008)=2009
t^2-2008t-2009=0
解得t=-1 或t=2009.
但是t=x^2+y^2不可能为负数， 所以x^2+y^2=2009
x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2
化简y(x+y)+(x+y)(x-y)-x^2
(x+y)(x-y)-(x-y)^2如题 (x+y)(x-y)-(x-y)^2
【2(x-y)(x-y)(x-y)-8(x-y)(x-y)(x+y)+6y(x-y)(x-y)]/2(x-y)(x-y)
因式分解x(x+y)(x-y)-x(x+y)^2
[(x-y)^2-(x+2y)(x-2y)]/y
计算:y-x分之x+y+x-y分之y-y-x分之2x-y
x^2(x-y)+(y-x)
x(x-y)2-(y-x)3
【(x-y)^2+(x+y)(x-y)】除以 2x
[(x-y)²+(x+y)(x-y)]除以2x
化简：[(x+y)(x-y)(x+y)^2-2y(x-2y)](-2y) 谢谢!
计算：[(x+y)(x-y)-(x-y)^2+2y(x-y)]/(-2y)
[(-x-y)(-x+y)-(x+y)^2-x(y-y^2)}÷1/2y
[2/3x-2/x+y(x+y/3x-x-y)]/x-y/x
化简：{2/3x-2/(x+y)[(x+y)/3x-x-y]}/(x+y)/x
计算2/3x-2/x+y(x+y/3x-x-y)/x-y/x
化简3x-2/(x+y)[(x+y)/3x-x-y]÷(x-y)/x