1. 390 : (4х + 3) = 26 2. 528 : (5х - 7) = 16
4х + 3 = 390 : 26 5х - 7 = 528 : 16
4х + 3 = 15 5х - 7 = 33
4х = 15 - 3 5х = 33 + 7
4х = 12 5х = 40
х = 12 : 4 х = 40 : 5
х = 3 х = 8
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
3. 594 : (8х - 55) = 18 4. 735 : (6х + 17) = 21
8х - 55 = 594 : 18 6х + 17 = 735 : 21
8х - 55 = 33 6х + 17 = 35
8х = 33 + 55 6х = 35 - 17
8х = 88 6х = 18
х = 88 : 8 х = 18 : 6
х = 11 х = 3
ж) 1/2 - 1/3 = 3/6 - 2/6 = 1/6
з) 3/5 - 1/3 = 9/15 - 5/15 = 4/15
и) 7/8 - 2/3 = 21/24 - 16/24 = 5/24
к) 3/4 - 4/7 = 21/28 - 16/28 = 5/28
л) 9/16 - 11/24 = 27/48 - 22/48 = 5/48
м) 11/12 - 11/18 = 33/36 - 22/36 = 11/36