## Pre-Algebra Tutorial

#### Intro

This tutorial is to introduce students to the concept of having a variable in a problem. A variable can be identified as a letter such as X or Y in an equation. The goal for the equation with a variable is to figure out what the variable’s value is. In this equation we will be solving to find out what the variable X is equal to.

2x + 3 = 7

#### Solution

The goal in this problem is to get X by itself. In order to do this, you must figure out how to get rid of the other numbers on the left side.

2x + 3 = 7

First, we want to get rid of the +3. In order to do this, we must subtract 3.

2x + 3 = 7
– 3

But, in order for the equation to work, you must also subtract 3 from the other side. So, subtract 3 from the 7.

2x + 3 = 7
– 3  – 3
Therefore, our equation now looks like this:

2x = 4

Now, we have to get rid of the 2. Since the X is being multiplied by X, we must divide by two to get rid of the 2. We must do this on both sides just like we subtracted 3 from each side of the equal sign

2x = 4
/2  /2

2 divided by 2 is 1. And 4 divided by 2 is 2. So, the solution will end up being

1x = 2

Anytime a solution has a 1 in front of it and nothing else, the one can be dropped to become just X so the final solution is

X = 2 