Problem
Trabalhos Assunto \[ \begin{array}{r} 10 \\ +10 \\ \hline \end{array} \]
Solution
Step 1 ：\[\begin{array}{r} 10 \\ +10 \\ \hline \end{array}\]
Step 2 ：\[\begin{array}{r} 10 \\ +10 \\ \hline 20 \end{array}\]
Step 3 ：\(\boxed{20}\)
