Question

Rewrite 17/20 and 21/25, so that they have a common denominator then use <,>or = to order 17/20 and 21/25

Answer 1

The least common denominator is
20 = 2 * 2 * 5
25 = 5 * 5

The least common denominator has two 5s and two 2s.
LCD = 2*2*5*5 = 100

17/20 = 17 * 5/ 20*5 = 85 / 100
21/25 =  21* 4/25*4 = 84 / 100

Talk about close
17/20 > 21/25 <<<< answer

But I hate to have predicted that before hand.