Question

x^3+1/x^3=18 then find X+1/x​

Answer 1

Answer:

Let x+1/x = t

Cubing both sides

x^3 + 1/x^3 + 3(x+1/x) = t^3

Now,

x^3+1/x^3 = 18

but, x+1/x = t

so,

18+3t = t^3

Clearly,

t=3 satisfies this equation.

and hence,

x+1/x = 3

Hope this helps you !

Answer 2

I have wrote the answer in pic

Hope it helps