Question

81/88 × (6 - 1 13/15) × 1 19/21

Answer 1

81/88 × (6 - 1 13/15) × 1 19/21
81/88*(6-13/15)*19/21
81/88*77/15*18/21
27/8*7/5*19/21
27/8*1/5*19/3
9/8*1/5*19
171/40 
4 11/40 или 4,275