1. Section 1-1
Using Variables

2. What is a variable
Variable Rate Mortgage?
Variable Interest Rate?

3. What is a variable?
In mathematics it’s a symbol, usually a letter, that represents different numbers

4. What is an Expression? According to answers.com
The act of expressing, conveying, or representing in words, art, music, or movement; a manifestation: an expression of rural values.

5. What is an Expression?
Mathematical phrase that includes numbers, variables, and operation symbols

6. Then what is an Equation? What is the difference?
An equation is an expression with an equals sign
Does anyone
know what this is?

8. Example How about: 12 minus m? Is it: 12 – m or m – 12?
It’s actually 12 – m

9. Books out
Let’s open our books to page 5 and look at Example 3.

10. Example - #18
The perimeter of a square equals 4 times the length of a side.
Answer:
Define Variables:
p = perimeter and s = length of a side
Equation:
p = 4s

11. Example - #22 First Define the Variables: n = number of tapes c = cost
Which is dependent on the other?
Which variable needs the
other to tell them how to
act?

12. Example - #22 Number of tapes is independent Cost is dependant
What does that mean?
It means you need the number of tapes to figure out the cost.

13. Example - #22
C = 8.5n
Because the cost increases each time by $8.50 for each tape.

14. It’s Homework Time
Please spend the first 10 minutes working quietly