Question

what is the least common denominator of 5/6 and 2/9

Answer 1

list the multiples of of 6 and 9, then pick the least one out
6: 6, 12, 18, 24
9: 9, 18, 27
18 is your lcd (least common denominator)

Answer 2

Rewriting input as fractions if necessary:
5/6, 2/9

For (6, 9) the least common multiple (LCM) is 18.

Therefore, the least common denominator (LCD) is 18.

Rewriting as equivalent fractions with the LCD
15/18, 4/18