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If (x^2+1)/x = 7 find x^2+(1/x^2)

User Flowfree
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1 Answer

3 votes

Answer:

x²+(1/x²) = 47

Explanation:

by identity : (a+b)² = a²+b²+2ab

(x+1/x)²= x²+(1/x)²+2(x)(1/x)

(x+1/x)²= x²+(1/x²)+2....(1)

since : (x²+1)/x = 7

(x²/x) +(1/x) = 7

x + (1/x )= 7

put the value for : x +(1/x) in (1) :

49 = x²+(1/x²)+2

x²+(1/x²) = 47

User Zxcat
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