Description for Correct answer:
\( \Large a+b=5, ab=4, a^{3}+b^{3}=? \)

Therefore, \( \Large \left(a+b\right)^{3} = a^{3}+b^{3}+3ab \left(a+b\right) \)

\( \Large 5^{3} = a^{3}+b^{3}+3 \times 4 \times 5 \)

\( \Large a^{3}+b^{3}=125 - 60 = 65 \)