(2 2/7 * 3,8 * 1 1/5) / (1,9 * 2 2/5 * 9 1/7) = 1/4,
1) 2 2/7 * 3,8 * 1 1/5 = 16/7 * 38/10 * 6/5 = 1824/175 = 10 74/175,
2) 1,9 * 2 2/5 * 9 1/7 = 19/10 * 12/5 * 64/7 = 7296/175 = 41 121/175,
3) 10 74/175 : 41 121/175 = 1824/175 * 175/7296 = 1824/7296 = 1/4,
(0,64 * 0,081 * 0,5) / (0,09 * 0,25 * 0,16) = (4 * 2 * 9) / 10 = 72/10 = 7,2