Question

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 这道题谁会 过程要详细！

Answer 1

X2+Y2+8X+6Y+25=0
x²+8x+16+y²+6y+9=0
(x+4)²+(y+3)²=0
∴x+4=0 y+3=0
x=-4 y=-3
X2+4XY+4Y2分之X2-4Y2 减X+2Y分之X
=(x²-4y²)/(x²+4xy+4y²)-x/(x+2y)
=(x-2y)(x+2y)/(x+2y)²-x/(x+2y)
=(x-2y)/(x+2y)-x/(x+2y)
=(x-2y-x)/(x+2y)
=-2y/(x+2y)
=-2*(-3)/(-4-6)
=-6/(-10)
=3/5

Answer 2

X2+Y2+8X+6Y+25=0 , -> (x+4)^2+(y+3)^2=0
x=-4,y=-3
X2+4XY+4Y2分之X2-4Y2 减X+2Y分之X
=(x+2y)(x-2y)/(x+2y)^2
=(x-2y)/(x+2y)
=(-4+6)/(-4-6)
=-1/6

Answer 3

由X2+Y2+8X+6Y+25=0可得X2+8X+16+Y2+6Y+9=(X+4)^2+(Y+3)^2=0
所以X=-4，Y=-3
则X2+XY+4Y2分之X2-4Y2 减X+2Y分之X
=[(-4)^2-4*(-3)^2]/[(-4)^2+(-4)*(-3)+4*(-3)^2]-(-4)/[-4+2*(-3)]
=-57/80

Answer 4

(X+4)^2+(Y+3)^2=0
则X=-4，Y=-3代入后面的式子
你自己算一下对不对，因为你后面的那个写的有点点歧义，方法是这样的。我算出来是-57/80。
望采纳，谢谢。

Answer 5

X2++XY+4Y2
无法理解这个！