Question

24. If x + 1/x= 5, then find the value of xpower2+1/xpower2=?
(a) 26 (b) 23 (c) 30 (d) 22
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Answer 1

Answer:

(b) 23

Step-by-step explanation:

x + 1/x = 5

Squaring both the sides,

(x + 1/x)² = (5)²

Identity: (a + b)² = a² + 2ab + b²

x² + 2(x)(1/x) + 1/x² = 25

x² + 2 + 1/x² = 25

x² + 1/x² = 25 - 2

So x² + 1/x² = 23