10 4/15-([+7 1/10)=2 13/30

10 4/15 - (x + 7 1/10) = 2 13/30

х + 7 1/10 = 10 4/15 - 2 13/30

х + 7 1/10 = 10 8/30 - 2 13/30

х + 7 1/10 = 9 38/30 - 2 13/30

х + 7 1/10 = 7 25/30

х + 7 1/10 = 7 5/6

х = 7 5/6 - 7 1/10

х = 7 25/30 - 7 3/30

х = 22/30

х = 11/15