If x=1/3-x,x not equal to 3 then find x3+1/x3 - Maths - Expansions

Question

If x=1/3-x,x not equal to 3 then find x3+1/x3

Koka Sri Lakshmi Divya Sai · Accepted Answer

Dear Student

Givenx=13-x⇒1x=3-x⇒x+1x=3Now squaring on both sides⇒x+1x2=32⇒x2+1x2+2=9⇒x2+1x2=7We know that a3+b3=a+ba2+b2-ab⇒x3+1x3=x+1xx2+1x2-x1x                  =x+1xx2+1x2-1                 =37-1                 =36=18
Regards