Dalton watched 7 – 2 = <<7-2=5>>5 more movies.
Hunter watched 12 – 2 = <<12-2=10>>10 more movies.
Alex watched 15 – 2 = <<15-2=13>>13 more movies.
Altogether, they watched 2 + 5 + 10 + 13 = <<2+5+10+13=30>>30 different movies.
#### 30