Question

x^3+1/3^3=15 then find x+1/x​

Answer 1

x³ +1/x³ =18

(x+1/x)³-3x*1/x(x+ 1/x) =18

let x+ 1/x = a

a³-3a =18

a(a²-3) =18

a=3

x+1/x =3