1. Objective - To recognize and evaluate variable expressions and basic formulas.
What is a variable?
A variable represents an unknown value.
1) 3 + ___ = 10
2) = 9
These are all
variables
3) x = 12
4) = 8

2. Variable Expressions
Variable expressions consist of constants,
variables, and operations.
Example
Meaning
Operation

3. Evaluate the expression if a = 3, b = 4, and c = 5
1) ab - c 3)
(3)(4) - 5
2(3)
12 - 5
= 8 7
2) 2a(b - c) 4)
2(3)(4 - 5)
2(4 + 5)
2(3)(-1) 3
2(9) 18 -6 =
= 6 3 3

4. Formulas
Formula - an equation which defines the relation- ship of one variable to other variables or numbers.
Travelling to Las Vegas at an average speed of
60 miles/hour takes 5 hours. How far is Las Vegas?

5. Perimeter Perimeter - Distance around a geometric figure.
Find the perimeter of the triangle below.

6. Area Formulas
Find the area
Rectangle w 4 l 5
Parallelogram w l

7. Area Formulas
Find the area
Rectangle w 4 l 5
Parallelogram

8. Area Formulas
Find the area
Rectangle w 4 l 5
Parallelogram h b

9. Area Formulas
Find the area
Rectangle w 4 l 5
Parallelogram h b

10. Area Formulas Find the area Rectangle w 4 l 5 Parallelogram 8 h 7 b 10
Triangle

11. Area Formulas Find the area Rectangle w 4 l 5 Parallelogram 8 h 7 b 10
Triangle h b

12. Area Formulas Find the area Rectangle w 4 l 5 Parallelogram 8 h 7 b 10
Triangle h b

13. Area Formulas Find the area Rectangle w 4 l 5 Parallelogram 8 h 7 b 10
Triangle h b

14. Area Formulas Find the area Rectangle w 4 l 5 Parallelogram 8 h 7 b 10
Triangle h b

15. Area Formulas Find the area Rectangle w 4 l 5 Parallelogram 8 h 7 b 10
Triangle 7 h 5 b 8