Primary mathematics:Introduction to variables

A variable is any part of an equasion that replaces a number with something that can represent a number. For example, $$5+E=14$$. In this case, $$E$$ is the variable. You may have seen this before as $$5+$$__$$=14$$. To solve a variable including problem with one step, you have to get rid of the first number. So for example, take $$x+36=45$$. To get rid of 36, we need to create $$-36$$. We also need to balance the problem on both sides. Therefore, the problem looks somewhat like this:. Now you solve the problem vertically. So $$36+(-36)$$ equals 0, so we can get rid of that. Then we take $$45-36$$ which equals $$9$$. Therefore, $$x=9$$.

The same overall process goes for other operations, just remember: Addition is the opposite of subtraction and multiplication is the opposite of division. By doing the opposite of the operation in the equation, you eliminate the variable and come to an answer.