Найдите наименьший общий знаменатель дробей 3/8, 5/12 и 7/8 1) 2162) 723) 17284) 36​

4 2/3 * 6 - 2 23/42 * 3 1/13 + 2 1/8 * 1 29/51 = 23 45/91

1) 4 2/3 * 6 = 14/3 * 6 = 28

2) 2 23/42 * 3 1/13 = 107/42 * 40/13 = 2140/273 = 7 229/273

3) 2 1/8 * 1 29/51 = 17/8 * 80/51 = 10/3 = 3 1/3

4) 28 - 7 229/273 = 27 273/273 - 7 229/273 = 20 44/273

5) 20 44/273 + 3 1/3 = 20 44/273 + 3 91/273 = 23 135/273 = 23 45/91

(5 3/10 - 3 4/5 * 13/38) * 5/84 + 2 1/12 * 4/15 = 50/63

1) 3 4/5 * 13/38 = 19/5 * 13/38 = 13/10 = 1 3/10

2) 5 3/10 - 1 3/10 = 4 

3) 4 * 5/84 = 20/84 = 5/21

4) 2 1/12 * 4/15 = 25/12 * 4/15 = 5/9

5) 5/21 + 5/9 = 15/63 + 35/63 = 50/63  

40 : 2 = 20         180 : 2 = 90         60 : 2 = 30        140 : 2 = 70

20 : 2 = 10          90 : 2 = 45          30 : 2 = 15         70 : 2 = 35

10 : 2 = 5            45 : 3 = 15          15 : 3 = 5           35 : 5 = 7

5 : 5 = 1              15 : 3 = 5             5 : 5 = 1            7 : 7 = 1

                            5 : 5 = 1

40 = 2 * 2 * 2 * 5

180 = 2 * 2 * 3 * 3 * 5

60 = 2 * 2 * 3 * 5

140 = 2 * 2 * 5 * 7

НОК (40; 180; 60; 140) = 2 * 2 * 2 * 3 * 3 * 5 * 7 = 2520 - наименьшее общее кратное

2520 : 40 = 63;     2520 : 180 = 14;     2520 : 60 = 42;     2520 : 140 = 18

ответ: НОК = 2520.