21/73.5 is equal to .285714285714285714 and so on. 285714 is repeated after the decimal and never ends
735
LCD(21, 45) = 315
21 ÷ 7 = 3.
21
The composite factors of 735 are 15, 21, 35, 49, 105, 147, 245, 735
735
735
735
735
735
21 over 8
20/21