4 целых 4/15 - 2 целых 9/40

4 4/15  -  2 9/40 = 64/15  -  89/40 =  (64 × 8  -  89 × 3)/120 = 512/120  -  267/120 =  245/120 = 49/24 = 2 1/24

4 4/15-2 9/40=2  4*8-9*3/120=2  32-27/120= 2  5/120= 2  1/24