Question

if x^2+1/x^2=31/9. Find: x^3+1/x^3​

Answer 1

Answer:

Step-by-step explanation:

x^2+1/x^2=31/9

Or,(x+1/x)² -2x×1/x=31/9

Or,(x+1/x)² =31/9+2

Or,(x+1/x)² =31+18/9

Or,(x+1/x)² =49/9

Or,(x+1/x)=7/3

x^3+1/x^3​

(x+1/x)³ -3.x.1/x(x+1/x)

(7/3)³ -3×7/3

343/27-7

12.70-7=5.7