One of the first things a student learns in a basic algebra class is how to solve single variable equations. Also known as linear equations, these are the most elementary equations. The work is completed once you find the value of that one variable.

Many people have experience with single variable equations before they take an algebra class.  The difference was in the way the problem was presented to the student. Instead of presenting a problem that looks like "x + 6 = 10," the teacher may have used a setup like "___ + 6 = 10."  In grade school, you learned that you needed to place the number in the blank that gave you ten when six was added to it. Single variable equations can be thought of the same way.http://www.purplemath.com/modules/solvelin.htm 

When working with single variable equations, you need to isolate the numbers from the variables. You begin by putting the equation into simpler forms. In the problem below, "x" is the variable. To get the variable on its own, you will add, subtract, multiply or divide numbers on each side of the equation to reduce it to its simplest form. You would simplify the following problem as follows:

2x + 5 - 6  =  -17 - 2

2x - 1 =  -19

Each side is now in a simpler form.http://www.teacherschoice.com.au/maths_library/algebra/alg_21.htm 

Now that you have the equation in a simpler form, you want the variable to be on one side of the equal sign and the numbers on the other side. You do this by adding or subtracting numbers on each side of the equal sign. Remember that what you do on one side of the equal side, you must do the same thing on the other side.

2x - 1 = -19

Add +1 to each side 2x - 1 + 1 = -19 + 1 to get:

2x = -18

The number in front of the variable is called the coefficient.  To get the variable by itself, you divide each side of the equation by the coefficient.  

Divide each side by the coefficient of x: 2x/2 = -18/2

The result is x = -9

Once x is on its own on one side of the equal sign, the equation is solved.http://www.purplemath.com/modules/solvelin2.htm 

Once you have a value for x, you can check to see if you did your math correctly by putting the value of X into the original problem. The original problem was:

2x + 5 - 6  =  -17 - 2

Substituting -9 for x gives 2(-9) + 5 - 6 = -17 - 2

-18 + 5 - 6 = -17 - 2

-18 - 1 = -17 - 2

-19 = -19

The numbers are the same on each side of the equal sign, so -9 is the correct value for x.http://www.purplemath.com/modules/solvelin2.htm