## Process

One step equations involve an unknown (a variable) that is usually represented by a lower case letter such as x and an equality.

For example: x + 5 = 10.

To be able to solve a one-step equation, we need to isolate x, which means x has to one one side of the equation alone. For this we use inverse operations, which are two operations that undo each other. For example addition is inverse of subtraction and vice versa. So in our example the operation we have is addition, and the inverse of addition is subtraction. Therefore, in order to undo (x +5) we subtract 5 from (x + 5). However, to be able to preserve the equality, we must subtract 5 from the other side of it. Subtracting the same number from each side of an equation produces an equivalent equation, which are equations that have the same solution. As a result, by using the subtraction property we get

x + 5 - 5 = 10 - 5

which is an equivalent equation of

x + 5 = 10

that is to say they have the same solution. However, when we collect like terms and clean out our equation, we get x = 5. Here x is isolated and we can clearly can see the solution.

This lesson is taught in three class periods.

First period: Lecture and individual exercises. Homework is given.

Second Period: Solutions to homework. Project is assigned.

Third Period: Discussion of project results.