Solving an Equation
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Solving Math Problems With a Variable....5
Before attempting to solve an equation, remember that the more unknowns there are, the more complex the equation will be. Learn how to solve simple equations and how to solve for "x" with help from a math teacher in this free video series on math help and lessons.
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Video Transcript
So how does one solve an equation? Hi, I'm Jimmy Chang and I've been teaching college mathematics for nine years and solving equations aren't our most favorite things to do but once you see the process it's actually going to be pretty straight forward. Now, the more unknowns you have the more complex that makes an equation. But let's just start with the most introductory level and start off by solving an equation with one variable so you get to see exactly how the process starts to work. So, here's an illustration. Suppose you have the equation two x minus three is equal to seven. Now, the objective is to see two times what number and then minus three is equal to seven. Now, the first thing to do is you want to be sure, you want to find out what x has to be. So the very first thing that you always want to be on top of is make sure that the term with the x is by itself. So that mean, because the minus three has nothing to do with x, you want to move that number over to the other side. So what you want to do is because the number is subtracted by three on this left hand side, you want to go ahead and use the opposite operation to get rid of it. So, in other words since you're subtracting by three, you want to add three to this side. But in an equation you always want to preserve balance. So that means what you do to one side, you have to do the exact same thing to the other side. So that means if you add three to this side you have to add three to this side as well. So as a result you have two x which you never touched, negative three plus three, which completely cancels out, and then seven plus three you know is ten. And then all you have to do is ask yourself well two times what number is going to give you ten. Well if you're pretty solid in your multiplication tables, you know immediately that x is going to be five. Or here's the other way to do it. It's two time x. So if you want to get x by itself, again you use the opposite operation. So the opposite of multiplication is division so divide both sides by two. So as a result, two divided by two completely cancels. You have x equals two and ten divided by two is going to give you five. So the missing answer that you're looking for is five. So, I'm Jimmy Chang and that's an introduction on how to solve the equation.