# Welcome to Algebra I: Solving Literal Equations

16 minutes

Hi, guys. Welcome to Algebra 1. Today's lesson's going to focus on solving literal equations. If you think back to pre-algebra, you had practice solving equations. You'll use that knowledge to get you through this one. You ready? Let's go.

(Describer) She uses a stylus on a screen.

Okay, before we get into literal equations, what they are, think back to linear equations. In pre-algebra, you probably solved something like this. You learned steps to get through this. You'd see, "solve for x." You've got 5x equals 20, so you think, when solving equations, the goal is to isolate the variable. You want to get the variable all alone. You have 5 times your variable, 5 times x. You have to do the opposite or the inverse operation-- in this case, of multiplying. The opposite of multiplying by 5 would be to divide by 5, so you'd divide both sides of your equation by 5.

(Describer) She writes.

On the left, the 5s would cancel out, so you'd be left with x equals-- and then 20 divided by 5 is 4. In pre-algebra you learn to solve one-step equations. We can solve them in one step. Okay? All right. Continuing back on memory lane, let's look at this.

(female describer) Title: Solve for x. 2/3x equals 4.

(Describer) Title: Solve for x. Two-thirds x equals four.

(Describer) Number One: Solve for b. A equals one-half bh. Number Two: Solve for w. V equals Lwh.

(female describer) 1. Solve for b: A equals 1/2 bh 2. Solve for w: V equals lwh. Okay, let's see how you did. Get the pointer tool back. On the first one, you're solving for b. I got b equals 2a divided by h. On the second one, we were solving for w. I got w equals v divided by lh, okay? I'll show you how I got those; I'll show my work. Let's get the pen; okay, here we go.

(Describer) Number One:

I was solving for b. Let's move things out of the way and get room to work. Let's get that out of the way, and let's move this up. There we go. I want to get b by itself, so I look at my problem and see what's going on with b. I think I'll scoot that over more. First, I spot that fraction. Get that out of the way. Think about that fraction as 1 divided by 2. That hints that, to get rid of it-- or you'll hear people say "clear" their fraction-- I need to multiply both sides by 2. On the right, my 2s cancel out, and I'm going to write bh, because that 1 as a coefficient isn't changing anything. And then on the left I have 2 times a. That's 2a. I'm trying to solve for b. I have 2a equals b times h. The opposite of multiplying by h--divide by h. Divide the right side and the left side by h. On the right, your "h"s cancel out. So you're left with b. And on the right, 2a divided by h. You noticed, I reversed it when I wrote the answer. This one is acceptable also, okay? Let me show you how I got that next one. Let's move some things out of our way. Move that. This time they're connected, okay. I'll rewrite that so I won't get that too crowded. V equals l times w times h. I'm solving for w. What's going on here? I have v equals l times w times h. I want to get w by itself. It's being multiplied by l and h. What's the opposite of multiplying by l and h? Divide. I'll divide the right side by lh and then the left side. What I do to one side, I do to the other. On the right, my "l"s cancel, my "h"s cancel, and I just have w. On the left, v divided by lh. On the answers, I reversed these, but this is fine too. Whichever way you want to write it, okay?

(Describer) V divided by Lh equals w.

All right, guys. I hope you feel confident about solving literal equations. I hope to see soon for more Algebra 1. Bye.

(Describer) Accessibility provided by the US Department of Education.

• X Showing Result 0 of 0

Transcript Options

Now Playing As: Captioned (English) (change)

In this program, students learn that equations with several variables are called literal equations. These equations use variables to represent known values like distance, time, interest, and slope. Part of the "Welcome to Algebra I" series.

## Media Details

Runtime: 16 minutes