(7/8 - 1/4 ) + (11/12-6/8) = 19/241)7/8 - 1/4 = (7 × 1 - 1 × 2)/8 = 7/8 - 2/8 = 5/8
2)1/12 - 6/8 = 11/12 - 3/4 = (11 × 1 - 3 × 3)/12 = 11/12 - 9/12 = 2/12 = 1/6
3)5/8 + 1/6 = (5 × 3 + 1 × 4)/24 = 15/24 + 4/24 = 19/24
(4/7+1/3)-(7/8-4/7) = 1 13/168
1)4/7 + 1/3 =(4 × 3 + 1 × 7)/21 = 12/21 + 7/21 = 19/21
2)7/8 - 4/7 =(7 × 7 - 4 × 8)/56 = 49/56 - 32/56 = 17/56
3)19/21 - 17/56 = ( 29 × 8 - 17 × 3)/168 = 232/168 - 51/168 = 181/168 =
1 13/168