\[\boxed{\mathbf{16.}}\]
\[28 + x = 55\]
\[x = 55 - 28\]
\[x = 27.\]
\[Проверка.\]
\[28 + 27 = 55\]
\[55 = 55.\]
\[x + 17 = 62\]
\[x = 62 - 17\]
\[x = 45.\]
\[Проверка.\]
\[45 + 17 = 62\]
\[62 = 62.\]
\[x + 36 = 84\]
\[x = 84 - 36\]
\[x = 48.\]
\[Проверка.\]
\[48 + 36 = 84\]
\[84 = 84.\]
\[49 + x = 73\]
\[x = 73 - 49\]
\[x = 24.\]
\[Проверка.\]
\[49 + 24 = 73\]
\[73 = 73.\]
\[66 + x = 71\]
\[x = 71 - 66\]
\[x = 5.\]
\[Проверка.\]
\[66 + 5 = 71\]
\[71 = 71.\]
\[x + 83 = 92\]
\[x = 92 - 83\]
\[x = 9.\]
\[Проверка.\]
\[9 + 83 = 92\]
\[92 = 92.\]