回答下面的数学题,要准确率,不要跑堂,X已知X²+3X+1=0,求(1)x+1/x,(2)x²+1/x²+2x+2/x的值前面一个x是多打的

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回答下面的数学题,要准确率,不要跑堂,
X已知X²+3X+1=0,求(1)x+1/x,(2)x²+1/x²+2x+2/x的值
前面一个x是多打的

(1)将方程X²+3X+1=0两边同时除以x得:x+3+1/x=0 ∴x+1/X=-3
(2)将方程x+1/X=-3两边平方得:x²+2+1/x²=9
∴x²+1/x²=7
∴x²+1/x²+2x+2/x=7-2×3=1

???

(1)将方程X²+3X+1=0两边同时除以x得: x+3+1/x=0 ∴x+1/X=-3
(2)将方程x+1/X=-3两边平方得:x²+2+1/x²=9
∴x²+1/x²=7
∴x&#...

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(1)将方程X²+3X+1=0两边同时除以x得: x+3+1/x=0 ∴x+1/X=-3
(2)将方程x+1/X=-3两边平方得:x²+2+1/x²=9
∴x²+1/x²=7
∴x²+1/x²+2x+2/x=7-2×3=1

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第一题:两边同除x得-3
第二题:由一知x+1/x=-3,取平方得x²+1/x²=7,2x+2/x得-6,综上,得1。

(1). x+3+1/x=0(两边同时除以x),所以x+1/x=-3
(2). x^2+1/(x^2)=(x+1/x)^2-2=7
所以为7-2*3=1

(1)把原试同时除以一个x,达到x+3+1/x=0,所以x+1/x=-3
(2)把x+1/x平方后得到x*2+2+1/x*2=9,所以x*2+1/x*2=7
然后把x+1/x乘以2得到2x+2/x=-6,所以原式的值为7-6=1
(打不来平方符号,敬请谅解)

(1).将式子除以一个x,得x+3 1/x=0所以,x 1/x=-3 (2).将式子分为两个部分求。=(x²+1/x²) 2(x 1/x),后面的一部分已经由第一问可得了,第一部分是将x 1/x平方一下,就可以得到x² 1/x²=7,所以之和为1。

方程X²+3X+1=0两边同时除以x
则(1)x+1/x=-3
(2)原式=(x+1/x)^2-2+2(x+1/x)
=9-2-6
=1

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