1) (85) 7/30 - (83) 5/18 = (85) 21/90 - (83) 25/90 = (84) 111/90 - (83) 25/90 =
= (1) 86/90 = (1)43/45
2) (1)43/45 : (2)2/3 = 88/45 : 8/3 = 88/45 * 3/8 = 11/15
3) 11/15 : 0,04 = 11/15 * 25 = 55/3
(36)2/3 % ------- 55/3
100 % -------- x
x = 55/3 * 100 : (36)2/3 = 55/3 * 100 : 110/3 = 50