 This video is going to talk about fractions and equations and how to handle that. Well, the first thing we need to talk about is least common denominator because we're going to need that in order to be able to solve these equations. So when you're looking at a least common denominator, you're looking at the denominators and here we have a 6 and a 3 and we want to list the multiples of those. So 6 would be 6 and then 6 times 2 is 12 and 6 times 3 is 18 and 6 times 4 is 24 and we'll see if that's enough. And then 3 would be 3 and 3 times 2 is 6. Oh, and we can see right there, all of a sudden I have listed something common to both of these already. So the least common denominator would be 6. And sometimes you have more than 2, so you have to consider all of them and find what they all have in common. So if I look at this next example, I've got 2, 5, and 4 as my denominators. I don't care what the top is right now. I'm just looking at the bottom to find the least common denominator. So we have 2 4, 6, 8, 10, 12, 14, I might even need more than this, 18, 16, 18, 20, 22, and so on. For 5 we have 5, 10, 15, 20. I've come up with one that's common, so let's see if I can find anything common with 4. 4 would be 4, and then 8. 4 times 3 is 12, 4 times 4 is 16, and 4 times 5 is 20. So I've got a 20 in all three of these when I list their multiples. So the least common denominator is that common multiple of 20.