What is a variable?

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) 6 + = 9 These are all variables 3) 8 + x = 12 4) 5 + = 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) + 4 2 6 + 4 2 12 - 5 6 + 2 = 8 7 2) 2a(b - c) 4) 2(3)(4 - 5) 2(4 + 5) 2(3)(-1) 3 18 2(9) -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. Objective- To simplify expressions involving exponents Exponent Base Write the following using exponents. 1) 3) 4 5 7 10 2) 4) 3 2 (-3) -12

7. Write in words how each expression should be read. 1) “Four to the third power” or “Four cubed” 2) “Eight and two hundredths squared” 3) “The fourth power of negative seven” 4) “The opposite of six to the fifth power”

8. Write the following expression without using exponents. Do not simplify. 1) “Three and seven thousandths cubed” (3.007)(3.007)(3.007) 2) “The opposite of four and one-third squared” 1 1 - (4 ) (4 ) 3 3 3) 6) -3(y)(y) (-7)(-7)(-7)(-7) 4) 7) - 7 7 7 7 (-3y)(-3y) 5) 8) (x + 8)(x + 8) (5y)(5y)

9. Simplify the following. -10,000 16 1) 6) +10,000 2 2) 7) -64 24 3) 8) -64 -36 4) 9) 16 1 5) 10)

10. Evaluate the following if a = 2, b = 3, c = 4, and d = 5 1) 4) 4 2 5 - (2) (3) + (2)(4)(5) 5 - 16 = -11 9 + 40 = 49 2) 5) 2 2 2 2 (2 3) - 5 (2) - (3) 36 - 25 = 11 4 - 9 = -5 3) 6) 2 2 2 2 (4) + (2) (4) - (2) + 5 16 + 4 = 20 16 - 4 + 5= 17