\[\boxed{\mathbf{3.}\mathbf{53.ОК\ ГДЗ - домашка\ на\ }5}\]
Пояснение.
Решение.
\[\textbf{а)}\ (206 + a) - 77 =\]
\[= (206 - 77) + a = 129 + a\]
\[\textbf{б)}\ (189 + c) - 63 =\]
\[= (189 - 63) + c = 126 + c\]
\[\textbf{в)}\ (z - 27) + 74 =\]
\[= z - 27 + 74 =\]
\[= (74 - 27) + x =\]
\[= z + 47\]
\[\textbf{г)}\ (t - 39) + 118 =\]
\[= t - 39 + 118 =\]
\[= (118 - 39) + t = t + 79\ \]