Question

If $x ^ 2 + 1 / x ^ 2 =23$ find the value of $x + 1 / x$

• A. 9
• B. 7
• C. 5
• D. 4

Answer 1

Answer:

C. 5

$(x+1/x)^2=x^2+1/x^2+2$

$(x+1/x)^2=23+2$

$(x+1/x)^2=25$

$x+1/x=\sqrt{25}=5$