Question

What is the least common denominator in the equation below?

1) 2
2) 9
3) 12
4) 36

Answer 1

To find the LCD, find the prime factors of each denominator, group them so each column is a new factor, and multiply all together:

4 = 2 x 2
2 = 2
3 = 3

2 x 2 x 3 = 12

Answer is 3) 12.