Сравнить дроби 3/5 и 21/40 7/12 и 39/48 1/17 и 3/51 3/8 и 5/6

1) 3/5 = 3*8/5*8 = 24/40
24/40 > 21/40

2) 7/12 = 7*4/12*4 = 28/48
28/48 < 39/48

3) 1/17 = 1*3/17*3 = 3/51
3/51 = 3/51

4) 3/8 = 3*3/8*3 = 9/24
5/6 = 5*4/6*4 = 20/24
9/24 < 20/24