Пошаговое объяснение:

4/9 и 1/6 => (4*4)/(9*4) и (1*6)/(6*6) => 16/36 и 6/36

1/6 и 2/15 => (1*5)(6*5) и (2*2)/(15*2) => 5/30 и 4/30

5/12 и 7/16 = (5*4)/(12*4) и (7*3)/(16*3) => 20/48 и 21/48

3/4 и 5/18 => (3*9)/(4*9) и (5*2)/(18*2) => 27/36 и 10/36