\[\boxed{\mathbf{14}.}\]
\[1)\ (123 + 78) + 177 =\]
\[= (123 + 177) + 78 =\]
\[= 300 + 78 = 378\]
\[2)\ 15\ 083 + (4917 + 6542) =\]
\[= (15\ 083 + 4917) + 6542 =\]
\[= 20\ 000 + 6542 = 26\ 542\]