Hi Guest!
Hint:
\(a^3+b^3=(a+b)(a^2+b^2-ab)=(a+b)((a+b)^2-2ab-ab)=(a+b)((a+b)^2-3ab)\)
Thus, \(a^3+b^3=14((14)^2-3ab)=14(196-3ab)\)
So:
\(\text{Given: }a^3+b^3 =812+ab \\ \implies 14(196-3ab)=812+ab\)
Now try to solve it from here :)
I hope this helps