use the correct order of operations to evaluate algebraic expressions (af 1.2) use algebraic...

1.1 Evaluating Algebraic

Expressions

Use the correct order of operations to evaluate

algebraic expressions (AF 1.2)

Use algebraic terminology correctly (AF 1.4)

Objective:

Words to know…

Expression a mathematical phrase that contains operations, numbers, and/variables.

Evaluate

a letter that represents a value that can change or vary.

Numerical expression

contains only numbers

Variable

substitute a given number for the variable

contains one or more variables.Algebraic expression

Evaluating Algebraic

Expressions with One Variable

x – 5 for x = 12

12 – 5

7

Order of Operations

PEMDAS: 1. Parentheses 2. Exponents3. Multiply and Divide from left to right.4. Add and Subtract from left to right.

Evaluating Algebraic

Expressions with One Variable Substitute 4 for y.

Multiply.

2y + 1 for y = 4

2(4) + 1 8 + 1

Add.9

Evaluating Algebraic Expressions with One Variable

6(n + 2) – 4 for n = 5, 6, 7

6(5 + 2) – 4

6(7) – 4

42 – 4

386(6 + 2) – 4

6(8) – 4

48 – 4

446(7 + 2) – 4

6(9) – 4

54 – 4

50

n Substitute Parentheses Multiply Subtract567

SUMMARY:What is the Order of operations?

Evaluating Algebraic

Expressions with Two Variables

A. 4x + 3y for x = 2 and y = 1 4(2) + 3(1) 8 + 3 11

B. 9r – 2p for r = 3 and p = 5 9(3) – 2(5) 27 – 10 17

Physical science

application

Use the expression 1.8c + 32 to convert the temperature from degrees Celsius to degrees Fahrenheit.

Boiling point of water at sea level: 100°C

Substitute 100 for c.

Multiply.

1.8(100) + 32

180 + 32

1.8c + 32

Add.212

100°C = 212°F

Water boils at 212°F at sea level.

Classwork

Evaluate each expression for the given value(s) of the variables.1. 6x + 9 for x = 3 2. x + 14 for x = 83. 4x + 3y for x = 2, y = 34. y(27 – x) for x = 19, y = 65. If n is the amount of money in a savings account, then the expression n + 0.03n can be used to find the amount in the account after it has earned interest for one year. Find the total in the account after one year if $500 is the initial amount.

2722

1748

$515