Сравните дроби ,приведя их к общему знаменателю : 1/5и5/18,12/24и1/2,7/20и10/15,5/12и3/4,2/5и3/8,6/25и1/4

1) 1/5 = (1 * 18) : (5 * 18) = 18/90;

5/18 = (5 * 5) : (18 * 5) = 25/90.

18/90 lt; 25/90, как следует 1/5 lt; 5/18.

2) 1/2 = (1 * 12) : (2 * 12) = 12/24;

12/24.

12/24 = 12/24; 1/2 = 12/24.

3) 7/20 = (7 * 3) : (20 * 3) = 21/60; 

10/15 = (10 * 4) : (15 * 4) = 40/60;

21/90 lt; 40/60; 7/20 lt; 10/15.

4) 3/4 = (3 * 3) : (4 * 3) = 9/12;

5/12;

9/12 gt; 5/12; 3/4 gt; 5/12. 

5) 2/5 = (2 * 8) : (5 * 8) = 16/40;

3/8 = (3 * 5) : (8 * 5) = 15/40.

16/40 gt; 15/40; 2/5 gt; 3/8. 

6) 6/25 = (6 * 4) : (25 * 4) = 24/100;

1/4 = (1 * 25) : (4 * 25) = 25/100.

24/100 lt; 25/100; 6/25 lt; 1/4.