77/91 in lowest terms is 11/13
84 over 77 in lowest terms = 12/11 or 1 1/11
The lowest term of 172 over 84 is 43/21 (in fraction form) or 21/21 (as a mixed number).
84 over 108 is 7/9
7/6
63/84 = = 3/4
226/29
1/3
84/1
77 + 84 = 161
21 over 25
(77/84) is the simplest form.You probably want the "lowest terms".That's (11/12).