1.
(3,65 - 2 3/4) : 3 + 17/40 * 12 = 5,4,
1) 3,65 - 2,75 = 0,9,
2) 0,9 : 3 = 0,3,
3) 17/40 * 12 = 204/40 = 5,1,
4) 0,3 + 5,1 = 5,4,
2.
(9,4 + 1 17/20) : 1 7/8 + 24 3/8 =
1) 9,4 + 1,85 = 11,25,
2) 11,25 : 1 7/8 = 1125/100 : 15/8 = 1125/100 * 8/15 = 90/15 = 6,
3) 6 + 24 3/8 = 30 3/8,
3.
(15 1/3 - 8 5/18) * 2 4/7 : 6 1/21 - 2 5/8 = 3/8,
1) 15 1/3 - 8 5/18= (15 - 8) + (1/3 - 5/18)= 7 + (6/18 - 5/18)= 7 + 1/18= 7 1/18,
2) 7 1/18 * 2 4/7 = 127/18 * 18/7 = 127/7 = 18 1/7,
3) 18 1/7 : 6 1/21 = 127/7 : 127/21 = 127/7 * 21/127 = 21/7 = 3,
4) 3 - 2 5/8 = 3/8,
4.
8,25 : 1,1 - (3 - 2,8 * 3/7) : 0,6 = 5,5,
1) 8,25 : 1,1 = 7,5,
2) 2,8 * 3/7 = 28/10 * 3/7 = 12/10 = 1 1/5 = 1,2,
3) 3 - 1 1/5 = 1 4/5,
4) 1 4/5 : 0,6 = 1,8 : 0,6 = 3,
5) 7,5 - 3 = 4,5