7 целых 2/15- (4-3целых7/15)+2целых12/15

1) 4 - 3 7/15 = 3 15/15 - 3 7/15 = 8/15 2) 7 2/15 - 8/15 = 6 17/15 - 8/15 = 6 9/15 3) 6 9/15 + 2 12/15 = 8 21/15 = 9 6/15 = 9,4