已知X方-2=0,求代数式(X方-1)方/X方-1 + X方/X+1的值

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已知X方-2=0,求代数式(X方-1)方/X方-1 + X方/X+1的值

已知X方-2=0,求代数式(X方-1)方/X方-1 + X方/X+1的值
已知X方-2=0,求代数式(X方-1)方/X方-1 + X方/X+1的值

已知X方-2=0,求代数式(X方-1)方/X方-1 + X方/X+1的值
x²-2=0
x²=2
x=±√2
原式=(2-1)²/(2-1)+2/(x+1)
=1+2/(x+1)
=(x+3)/(x+1)
=(x+3)(x-1)/(x+1)(x-1)
=(x²+2x-3)/(x²-1)
=(2+2x-3)/(2-1)
=2x-1
=2√2-1或-2√2-1

两个方程相减
x+y=-2
2x+2y=-4
3x+2y=k+1
x=k+5
y=-2-x=-x-7
x<0,y<0
k+5<0,k<-5
-x-7<0
x>-7
所以-7