Question

Find the least common denominator (LCD) 8/9 and 4/5

Answer 1

45

Explanation:

So since we are finding the LCD, we only look at the denominators, 9 and 5.

We can count until we find the denominator:

`9,18,27,36,45\\5,10,15,20,25,30,35,40,45`

So the LCD would be 45.

Answer 2

45

Explanation:

First we write the first 10 multiples of 9 (the first denominator) :

9,18,27,36,45,54,63,72,81,90

Now we write the first 10 multiples of 5 (the second denominator) :

5,10,15,20,25,30,35,40,45,50

As we can see 45 is the lowest number that appears in both list.

Therefore 45 is the LCD of 8/9 and 4/5