Dividing Equations

Video Transcript

"So, how do you divide equations? That sounds really complicated, doesn't it? Hi, I'm Jimmy. I've been teaching college math for nine years, and we're here to discuss how to divide equations. Now, oftentimes when you divide in equations, chances are likely that there's going to be some fractions involved, and you and I both know, that fractions aren't the most pleasant things to be around, but there's some ways to get around it, but it really involves your multiplication tables, and as well as the least common denominator, so here's an example, as to how you would divide in equations. Now, suppose you have 3x over 4 - 1/2= to 5, now what you want to do to solve this, is you could either tackle the fractions directly head on, or you could go with the easier route, by taking a look at your denominators, 4 and 2, and ask ourself, Well, what's the least common denominator? In other words, what number do both 4 and 2 go into? Well, 4 and 2 both go into the number 4, so here's how you use that number. Take every term and multiply all the terms by the number 4. Now, what you can see here, is that the 4's will cancel, and your fraction equation, becomes non-fractions. Check this out. The 4 and the 4, 4 and 4 reduces completely, so the 4's are actually canceled, so you're left with 3x. Now, the 4 and the 2, 4 divided by 2 is going to be 2, so the 4 becomes a 2, and the 2 just becomes a 1, so that really is completely canceled out, and so you have a -2 times 1, which is going to give you 2. Now, because on the other side, the 5 didn't really have a fraction, its' just a matter of multiplying the 4 and the 5, which is going to give you 20. Now, you don't have any more fractions, so solving the equation becomes much easier. All you need to do here, is to get x by itself, add 2 to both sides, so you now have 3x-2 2 is completely canceled out, and 20 2 is obviously 22, and last but not least, to solve for x, just divide both sides by 3, and so your final answer is going to be x equal to 22 thirds, so your final solution will be a fraction, but that's ok. You turned a fraction equation into a non- fraction equation, so I'm Jimmy, and that is exactly how you divide fraction equations."