Let $a, b \in \mathbb{R}$ each be a D993: Real number.

Then \begin{equation} \begin{split} (a + b)^5 = a^5 + 5 a^4 b + 10 a^3 b^2 + 10 a^2 b^3 + 5 a b^4 + b^5 \end{split} \end{equation}