EXAMPLE 2

1. EXAMPLE 2 Evaluate an expression Movies The total cost of seeing a movie at a theater can be represented by the expression a + rwhere ais the cost (in dollars) of admission and ris the cost (in dollars) of refreshments. Suppose you pay $7.50 for admission and $7.25 for refreshments. Find the total cost.

2. ANSWER The total cost is $14.75 EXAMPLE 2 Evaluate an expression SOLUTION a +r Total cost= Write expression. Substitute7.50 foraand 7.25for r. = 7.50 + 7.25 = 14.75 Add.

3. Power Words Product 1 1 1 1 3 5 5 2 2 2 2 c. z z z z z EXAMPLE 3 Read and write powers Write the power in words and as a product. seven to the first power a. 71 7 b. 52 five to the second power, or five squared one half to the third power,or one half cubed d. z5 zto the fifth power

4. ANSWER The total cost is $9.50. for Examples 2 and 3 GUIDED PRACTICE 5. WHAT IF? In Example 2, suppose you go back to the theater with a friend to see an afternoon movie. You pay for both admissions.Your total cost (in dollars) can be represented by the expression 2a. If each admission costs $4.75, what is your total cost?

5. Power Words Product 9 9 99 9 2 2 22 2 2 2 2 8. n4 nnnn for Examples 2 and 3 GUIDED PRACTICE Write the power in words and as a product. Nine to the fifth power 6. 95 7. 28 Two to the eighth power n to the fourth power