Question

What is the LCD of 5/6 and 2/9?

Answer 1

We look at denominators `6 and 9`

Explanation:

We factor them into primes:
`6=2*3` and `9=3*3`

Now we take all factors to their highest degree:
`2*3*3=18`

So `5/6=15/18` and `2/9=4/18`

And now we can add or subtract them, because they have a common denominator.