Example 1 Multiplying Integers a. 3 () 4 – Different signs, so product is negative. = 12 – b. () 3 – 6 – Same sign, so product is positive. = 18 c. () 3 – 4 – () 2 Multiply from left to right. = () 3 – 8 – Multiply. = 24
Example 2 Finding Powers of Integers a. () 4) 4 3 – Write as a repeated product. = () 3 – () 3 – () 3 – () 3 – Multiply from left to right. = 9 () 3 – () 3 – = () 3 –– 27 Multiply. = 81 b – Use order of operations. = ( – ) Evaluate power. = 81 –
Example 3 Evaluating an Expression Involving Multiplication MOVIES A stuntman working on a movie set falls from a building’s roof 90 feet above an air cushion. The expression 16t 2 90 gives the stuntman’s height (in feet) above the air cushion after t seconds. What is the height of the stuntman after 2 seconds? – + SOLUTION Evaluate the expression for the height when t 2. = 90+16t 2 – 90+ = 16 – ) 2) 2 ( 2 Substitute 2 for t. 90+ = 16 – )( 4 Evaluate the power.
Example 3 Multiply. Add. = = 64 – ANSWER After 2 seconds, the stuntman is 26 feet above the air cushion. Evaluating an Expression Involving Multiplication
Guided Practice for Examples 1, 2, and 3 Find the product – () 4 ANSWER – 20 ANSWER – () 3 – 3. () 7 – 3 – ANSWER 21 ANSWER () 8 – 2 – () 5
Guided Practice for Examples 1, 2, and 3 ANSWER – – Find the power. 5. () 2 – – 8. () 4 – 3 ANSWER 4 – 64 ANSWER – 64
Guided Practice 9. for Examples 1, 2, and 3 ANSWER 74 ft MOVIES In Example 3, what is the height of the stuntman after 1 second?