Algebra is a division of mathematics designed to help solve certain types of problems
quicker and easier. Algebra is based on the concept of unknown values called
variables, unlike arithmetic which is based entirely on known number values.

This lesson introduces an important algebraic concept known as the Equation.
The idea is that an equation represents a scale such as
the one shown on the right. Instead of keeping the scale balanced with weights, numbers,
or constants are used. These numbers are called constants because they constantly have the same value.
For example the number 47 always represents 47 units or 47 multiplied by an unknown number.
It never represents another value.

The equation may also be balanced by a device called a variable. A variable
is an an unknown number represented by any letter in the alphabet (often x).
The value of each variable must remain the same in each
problem.

Several symbols are used to relate all of the variables and constants together.
These symbols are listed and explained below.

??? |
Multiply |

* |
Multiply |

/ |
Divide |

+ |
Add or Positive |

- |
Subtract or Negative |

( ) |
Calculate what is inside of the parentheses first. (also called grouping symbols) |