Proportions

Hello, everyone. Today we will be reviewing proportions. Our proportion that we're going to be working with today is going to be 5 over 20 is equal to X over 50. Now, in order to solve this proportion, what's our first step going to be? Well, it's going to be cross multiplication. And how do we cross multiply? We're going to multiply the numerator. By the denominator on each fraction or ratio depending on how you'd like to call them. So for multiplying our numerator here 5 times 50, what do we get? We get two 50. 5 times 50. And if we multiply 20 times X, that gives us 20 X so that's our first step in solving for this proportion. Now our second step is going to be to divide. We're going to divide this 20. With the two 50. So we're dividing. Two 50 divided by 20. Two 50 divided by 20 is 12 .5. So what are we left with? X is equal to 12.5. Now that we have our answer, we could do one more step. And that step is going to be to check artwork. Now that to check our work, all we do is plug in this 12 .5, where the X was because we said that X is equal to 12.5. So let's plug it in and then see if everything checks out. So our original proportion was 5 over 20 is equal to remember we said we're plugging in the 12.5 over 50. So if we cross multiply the same way we did earlier, 5 times 50 and 20 times 12.5, what do we get? 5 times 50, we already said that's two 50. 20 times 12.5 is also two 50. So this is right. And this is right. That means our answer is correct. So we got it. Now that you give it a try, you got this.