1. Inverse Operations
Algebraic equations include a variable. A variable is a letter that represents
an unknown number. A variable could represent a single amount, such as the number of
Tommy’s pencils, or a combined amount, such as the amount of Tommy’s pens and
pencils. In order to solve equations, it’s important to understand what the variable
represents.
The goal today is to teach you how to solve two-step equations. There are a variety
of methods and strategies to solve these types of problems, but today we are going to
discuss one: the Inverse Operations method. Remember that equations have an equal sign.
It’s also important to remember that everything on one side of the equal sign is equal to, or
the same as, everything on the other side of the equal sign. Also, remember that inverse
operations are opposite operations. Addition and subtraction are inverses of each other, as
well as multiplication and division. Let’s use Inverse Operations to solve a problem.
“Your class is going on a trip to the state fair. The trip costs $52. Included in that price is
$11 for a concert ticket and the cost of 2 passes, one for the rides and one for the games.
Each of the passes cost the same price. We could write an equation to represent the
situation, with x representing the price of each pass.”
2x + 11 = 52
First, I need to isolate the 2x by subtracting 11. To keep it balanced, I subtract 11 from both
sides.
That leaves a total of: 2 x = 41. The inverse of multiplying by 2 is dividing by 2, so I divide
both sides by 2.
So each pass cost $20.50