Сократите дроби: a) 20/118 , 236/444 , 66/102 , 128/28 б) 108/72 , 36/243 , 120/168 , 720/640 . решите !

a) 
20/118 = 10/59
236/444 = 59/111
66/102 = 22/34
128/28=32/7=4 4/7

б) 
108/72 = 27/18 = 1 1/2 = 1,5
36/243 = 4/27
120/168 = 15/21
720/640 = 9/8 = 1 1/8 = 1,125