\(\dfrac{10}{16}=x+\dfrac{9}{24}\)
\(\dfrac{5}{8}=x+\dfrac{3}{8}\)
\(x=\dfrac{5}{8}-\dfrac{3}{8}\)
\(x=\dfrac{2}{8}\)
\(x=\dfrac{1}{4}\)
\(\dfrac{10}{16}=\dfrac{x+9}{24}\)
\(\Leftrightarrow x=\left(\dfrac{10}{16}x24\right)-9\)
\(\Leftrightarrow x=\dfrac{240}{16}-9=6\)