Answer :
(x + 1/x)^2 = 20^2
x^2+(1/x)^2+2 x x x 1/x=400
x^2+1/x^2+2x/x=400
thereforex^2+1/x^2=400-2=398
sry tried the second one but im not able to do
x^2+(1/x)^2+2 x x x 1/x=400
x^2+1/x^2+2x/x=400
thereforex^2+1/x^2=400-2=398
sry tried the second one but im not able to do