помогите решить пример на дроби 6 6/10* 3/4:2 2/5*2 1/5

6 6/10 * 3/4 : 2 2/5 * 2 1/5 = 4 43/80

1) 6 6/10 * 3/4 = 66/10 * 3/4 = 198/40 = 4 38/40 = 4 19/20

2) 4 19/20 : 2 2/5 = 99/20 : 12/5 = 99/20 * 5/12 = 99/48 = 2 3/48 = 2 1/16

3) 2 1/16 * 2 1/5 = 33/16 * 11/5 = 363/80 = 4 43/80