1) а) 4,2 / 25,2 = 42/10 : 252/2 = 42/10 х 2/252 = 1/30
б) 2 2/5 : 1 1/15 = 12/5 : 16/15 = 12/5 х 15/16 = 3/2= 1 1/2
в) 1,56 : 2 1/6 = 156/100 : 13/6 = 156/100 х 6/13 = 18/25
2) m - 2/11m = 9,9
9/11m = 99/10
m = 99/10 : 9/11
m = 99/10 x 11/9
m = 12,1
3) 360 : 8/9 = 360 х 9/8 = 405 га
4) 100% - 85% = 15%
15% = 18км
100 х 18 : 15 = 120 км
5) 9,72 : 0,3 = 32,4 (80%)
32,4 : 80 = 40,5
к = 40,5