\[x - первое\ число;\ \ \ \]
\[3x - второе\ число.\]
\[x + 3x = 144\]
\[4x = 144\ \ \ \ |\ :4\]
\[x = 36.\]
\[3x = 3 \cdot 36 = 108.\]
\[Ответ:36;108.\ \]