а)(13 1/7+5 2/3):5/7 =26 1/3

1)13 1/7 +5 2/3 = 18 17/21

2) 18 17/21 : 5/7 = 26 1/3

б)(7 1/6-2 5/8)•12=

1) 7 1/6-2 5/8 =4 13/24

2) 4 13/24•12= 54 1/2