# Equation Basics

## What does it mean?

### Definitions:

An algebraic expression is obtained by performing a finite number of the following operations on symbols representing numbers: addition, subtraction, multiplication, division or raising to the nth power.

## What does it look like?

A general example to help you recognize patterns and spot the information you're looking for

A mathematical expression can have variables as part of the expression. If x=3, and y=5, the expression $$7x + y - 4$$ becomes $$(7 * 3) + 5 - 4$$ which is equal to $$21 + 5 - 4$$ or $$22$$

## You'll use it...

We use them when we want to figure the out cost of multiple items.

## Video

### Example: Solving Equations

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Length: 8:41 Opens in player window

## Video

### Variables and Expressions 1

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Length: 2:00 Opens in player window

## Video

### Evaluate a Formula Using Substitution

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Length: 1:15 Opens in player window

## Video

### Variables Expressions and Equations

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Length: 6:55 Opens in player window

## Video

### Examples of evaluating variable expressions

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## Video

### Rearrange formulas to isolate specific variables

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Length: 2:29 Opens in player window