Math 7 - Algebraic Expressions

Algebraic Expressions

Variable
• represents an unknown quantity.

• any letter can be used, usually lower case.

Eg. Tickets for a movie cost $10.
The cost of a bunch of tickets
would be 10t, where t represents the number of tickets purchased.

• In the example above, t is the variable 10 t is an algebraic expression. Here are several more….

• n + 6……some number plus six more, or your age 6 years
from now.


• b/20 …..some number divided by twenty


• 8b …..8 is multiplied by some number.

• f – 11 ….eleven less than a number.

Expressions have parts:

Eg. 6n – 9

6 - is the numerical coefficient of the variable.
n - is the variable.
2 - doesn’t change so it’s called the constant.


*Note:
Students must replace the variable with a given number.
When substituting into an expression, substitute with
brackets.


Eg. 6y + 9 (y = 7)

6 (7) + 9

42 + 9

=51