Divide. Evaluate power – 3 = – 3 EXAMPLE – 3 = 3 2 – – 3 = 6 – 3 Multiply. Evaluate expressions Multiply and divide from left to right. STEP 3 Evaluate the expression – There are no grouping symbols, so go to Step 2. STEP 1 Evaluate powers. STEP 2
STEP 4 Add and subtract from left to right. 6 – 3 = 3 EXAMPLE 1 Subtract. ANSWER The value of the expression – 3 is 3. Evaluate expressions
GUIDED PRACTICE for Example 1 1. Evaluate the expression 20 – 4 2 ANSWER Evaluate the expression ANSWER Evaluate the expression ANSWER 3. 10
GUIDED PRACTICE for Example 1 4. Evaluate the expression – 4 ANSWER 4. 47
24 – (9 + 1) = 2[9] EXAMPLE 2 Evaluate expressions with grouping symbols Evaluate the expression. a. 7(13 – 8) = = 35 Subtract within parentheses. Multiply. b.b. 24 – ( ) = Evaluate power. =24 – 10 Add within parentheses. = 14 Subtract. c. 2[30 – (8 + 13)] = Add within parentheses. Subtract within brackets. = 18 Multiply. 7(5) 2[30 – 21]
EXAMPLE 3 Evaluate an algebraic expression Evaluate the expression when x = 4. 9x 3(x + 2) Substitute 4 for x. Add within parentheses = Multiply. =2 Divide. = 3(4 + 2) =
GUIDED PRACTICE for Examples 2 and 3 Evaluate the expression. 5. 4(3 + 9)= (8 – 2 2 ) = [( 9 + 3) 4 ] = 6
GUIDED PRACTICE for Examples 2 and 3 Evaluate the expression when y = 8. = 61 y 2 – 38. = 3 12 – y – 19. = 9 10y + 1 y
Standardized Test Practice EXAMPLE 4
SOLUTION Substitute 1.25 for j and 2 for s. = 12( ) + 30 Multiply within parentheses. = Multiply. = 123 Add. The sponsor’s cost is $123.The correct answer is B.. AB C D ANSWER = 12(7.75) + 30 Add within parentheses. = 12( ) (3j +2s) + 30
GUIDED PRACTICE for Example WHAT IF? In Example 4, suppose the number of volunteers doubles. Does the sponsor’s cost double as well? Explain. The sponsor’s cost is $216. No; the total cost of the juice drinks and sandwiches will double, but the cost of the trash bags will not. ANSWER