1.3 What you should learn Why you should learn it Order of Operations GOAL 1 Use the order of operations to evaluate algebraic expressions. GOAL 2 Use a calculator to evaluate real-life expressions such as calculating sales tax. Why you should learn it To solve real-life problems, such as calculating the cost of admission for a family to a state fair.
1.3 Order of Operations 1 GOAL USING THE ORDER OF OPERATIONS WHAT IS THE ORDER OF OPERATIONS? It’s the method we use to evaluate an expression involving more than one operation: 1. 2. 3. 4. Grouping symbols (innermost first, work to the outermost) Powers Multiplication and division Addition and subtraction left to right left to right
Extra Example 1 Evaluate the expression when x = 3. 1. 2.
Perform the operations from What happens when operations that have the same priority appear in the same expression, such as 5 – 4 +1? 5 – 4 + 1 1 + 1 2 5 – 4 + 1 5 – 5 Which is correct? Perform the operations from left to right! EXAMPLE 2
Summary ORDER OF OPERATIONS Perform operations within grouping symbols, beginning with the innermost first. Simplify powers. Multiply and divide from left to right. Add and subtract from left to right. EXAMPLE 3
Extra Example 3 Simplify the expression. Click to see each step. Hint: The fraction bar serves as a grouping symbol. Simplify the numerator and denominator separately before the final step. Simplify the power. Simplify the numerator. Work from left to right. Subtract. Simplify.
Checkpoint 1. Evaluate the expression when x = 5. a. 2x2 + 8 b. 100 ÷ x2 + 6 58 10 Simplify the expression. a. 25 + 10 – 8 b. 24 ÷ 2 • 3 c. 36 – 6 ÷ 3 + 3 27 36 37 Simplify the expression. 4
1.3 Order of Operations 2 EVALUATING EXPRESSIONS WITH A CALCULATOR GOAL 2 EVALUATING EXPRESSIONS WITH A CALCULATOR The point: YOU must know how your calculator works. Be sure you work through the examples and understand YOUR calculator. EXAMPLE 4 EXAMPLE 5
Checkpoint Simplify each expression using your calculator. Identify the order in which the operations are performed. 1. 2. 3. 11; division, subtraction, addition 8; subtraction, division, addition ≈1.29; subtraction, addition, division
QUESTIONS?