Приведем дробь к общему знаменателю:

1) 2/9 и 5/12;

2 * 4/(9 * 4) и 5 * 3/(12 * 3);

8/36 b 15/36.

2) 2/7 и 3/14;

4/14 и 3/14.

3) 5/9 и 2/27;

15/27 и 2/27;

4) 3/8 и 2/9;

27/72 и 16/72;

5) 3/19 и 2/3;

9/57 и 18/57;

6) 2/15 и 5/18;

12/90 и 25/90;

7) 2/9 и 3/4;

8/36 и 27/36;

8) 5/12 и 5/16;

80/192 и 75/192;

9) 7/12 и 4/15;

35/60 и 16/60.