anna019010 9 2/5 - (8 1/3 - 7 1/4 + 5 1/6) = 2 9/10
8 1/3 - 7 1/4 = 25/3 - 28/4 = (100-84)/12 = 16/12
16/12 + 5 1/6 = 16/12 + 31/6 = (16+62)/12 = 78/12
9 2/5 - 78/12 = 47/5 - 78/12 = (564-390)/60 = 174/60 = 2 54/60 = 2 27/30 = 2 9/10