(1)..7/10 + 1/10 = 8/10 = 4/5
(2)..5/9 + 4/9 = 9/9 = 1
(3)..8/15 + 3/15 = 11/15
(4)..9/14 + 3/14 = 12/14 = 6/7
(5)..3/5 + 8/5 = 11/5
(6)..4/15 - 3/15 = 1/15
(7)..7/8 - 5/8 = 2/8 = 1/4
(8)..5/3 - 2/3 = 3/3 =1
(9)..7/8 - 4/8 = 3/8
(10)..1314/2010- 520/2010 = 794/2010 = 397/1005