Linear equations are equations with just one variable like "x". Linear equations are the simplest equations.
In general, to solve a linear equation for a given variable, you need to "undo" whatever has been done to the variable. You do this in order to get the variable by itself; in technical terms, you need to "isolate" the variable.

Solve x + 6 = –3

You want to get the x by itself; that is, you want to get "x" on one side of the "equals" sign, and some number on the other side.

What you can do is to subtract 6 from both sides of the equation, and you will get:

x + 6 - 6 = -3 + 6

Which will be:

x = -3 + 6, Or:

x = 3

The most important consideration with equations, linear or non-linear: whatever you do to the one side, you must do the exact same thing to the other side!

Solve x – 3 = –5

What you can do is to add 3 on both sides of the equation, and you will get:

x - 3 + 3 = -5 + 3

Which will be:

x = -2

Most linear equations require more than one step for their solution. For instance:

Solve 7x + 2 = –54

What you can do is:

First, subtract 2 from both sides:

7x = -54 - 2

Second, divide 7 from both sides:

x = (-54 - 2)/7, Or

x = -8