1)22,2: 5 2/7 - 2 3/5 2) (7 1/4 - 6 7/18) х 7,2 + 2,8 и 13/18 b + 1/6 b - 1/3 b и найдите значение при b= 1,8.

1. 1) 22,2: 5.2/7=22,2:(37/5)=111/5*5/37=3
2) 3-2.3/5 = 2/5 0,4

2. 1) 7.1/4-6.7/18 = 7.9/36-6.14/36 = 6.45/36-6.14/36 = 31/36
2) 31/36*72/10 = 31*2/10 = 62/10 = 6,2
3) 6,2+2,8 = 9

13/18 b +1/6 b - 1/3b = 13/18b+3/18b-6/18b = 10/18b=5/9b = 5/9*1,8 = 5/9*18/10 = 1