Total possible subcommittees = C(14,5)
Total possible subcommittees that contain no Repubs = C(6,5) [choose any 5 Dems from 6 ]
Total possible subcommittees that contain no Dems = C(8,5) [ choose any 5 Repubs from 8 ]
So...the total number of subcommittees that contain at least one member of either party =
C (14,5) - C(6,5) - C(8,5) = 1940