# Algebraic Expressions Examples

#### Variables as Unknown Quantities

Sometimes we're given some tantalizing information about a number, and we need to figure out what the number is.Sample ProblemFill in the blank: 2 + ? = 10.The answer is 8, since 2 + 8 = 10. Th...

#### Constants

Constants are quantities that do not change. They're like crotchety old curmudgeons, forever stuck in their ways.3, 57, 299, and are constants.π and e are also constants.
We can also...

#### Distributive Property

Suppose we have 3 baskets, each holding 2 apples and 4 oranges.This is the same number of apples and oranges as if we had a bag with 6 apples and a bag with 12 oranges. Except that we now mysteriou...

#### Factoring (Distributive Property in Reverse)

We can work the distributive property in reverse—we just need to check our rear view mirror first for small children.When we rewrite ab + ac as a(b + c), what we're actually doing is factori...

#### Combining Like Terms

You probably don't keep bananas in your sock drawer or toothpaste on your bookshelf. If you do, we can recommend a good therapist. Aside from it being an awful hassle to run from the bookshelf t...

#### Independent and Dependent Variables

Let's take a closer look at how independent and dependent variables work by working through some examples.Sample ProblemJim gets paid $10 per hour. The amount Jim gets paid in a week depends on...

#### Formulas

Here's video to help illustrate a few formulas.
It's been a loooong time since you've needed to deal with formula on a daily basis. You probably transitioned to solid foods at around five mont...

#### Evaluating Expressions by Substitution

Remember that a variable is like an empty box that's waiting for a number. Have you ever seen a box wait? Those things have unbelievable staying power.We call it substitution when we pu...

#### Evaluating Formulas by Substitution

As we mentioned, a formula has a dependent variable on one side and an expression involving the independent variable(s) on the other side. To evaluate a formula, we evaluate the expression contai...

#### In the Real World

I Like Practical Stuff; Why Should I Care?Hey, we like practical stuff, too! The great thing is that all of these formulas can be applied to real-world situations. That's good news if you live in...