 Now, before we get into larger problems, I want to show you one other technique, which is called cross-multiplying, which is super powerful when you're trying to reduce large problems or even small problems. Basically the way cross-multiplying works is as long as you have one fraction equal to another fraction, you can cross-multiply. You can take the denominator on this side, kick it up to the top on the other side and nominate it on this side, kick it up to the numerator on the other side. So the way it works is if you have, so when you have one fraction is equal to another fraction, what you can do is take this, kick it up here, and take this, kick it up here, okay? So in the end what you end up with is this box times that box is equal to this box, whatever is in there, times this, okay? It's as simple as this, it's super powerful, I'm going to do a couple of really quick examples of this and later on when we get into larger problems you'll see how it can help you out, reduce a few steps when you're trying to solve the problems, okay? So just an example for cross-multification, let's say you have something like this. Let's say you had 2 over x is equal to 5 over 3, right? So all you're going to do is grab this, multiply it up here, so as it goes up here, the 3 goes up here because this is multiplication, you're not changing signs, right? You only change signs with addition and subtraction, with cross-multification all you do is take the denominator here, kick it up to the numerator over there, kick the denominator here, kick it up to the numerator over there. So on this side it becomes 2 times 3, which is 6, and on this side it becomes 5x, right? Now you haven't finished solving this problem, you've got to get x by itself, so all you do is, so all you end up doing is dividing by 5 on both sides, right? Are we on the border? Good. Have a fraction equal to a fraction, so for example you couldn't have, you couldn't have something like this and cross-multiply. You couldn't have something like this and cross-multiply this way, because this gets in the way, the way you have to deal with this is, you have to add these guys first, you have to simplify one side to make sure it equals a fraction, and the other side has to be a fraction before you can cross-multiply, kick the denominators up to the numerator. So x plus 2, x over 5 plus, x over 2 plus 5 is equal to 6, that you can't cross-multiply the 2 up, you have to move the 5 over first, right? So you grab this guy, bring it over, it becomes minus 5, so you go 6 minus 5. On this side you move the 5 over already, so you've got x over 2, so you've got x over 2 is equal to 1, and now you can just cross-multiply up. Now this is as simple as this is going to get, right? So this guy just goes up here, so your final answer is x is equal to 2. So your final answer is going to be x is equal to 2, okay? We're slowly going to build up these problems and make them more difficult.