Introduction to Real Numbers and Algebraic Expressions 1.1

Introduction to Real Numbers and Algebraic Expressions
1.1 Introduction to Algebra
1.2 The Real Numbers
1.3 Addition of Real Numbers
1.4 Subtraction of Real Numbers
1.5 Multiplication of Real Numbers
1.6 Division of Real Numbers
1.7 Properties of Real Numbers
1.8 Simplifying Expressions; Order of Operations

1.1 INTRODUCTION TO ALGEBRA
a. Evaluate algebraic expressions by substitution.
b. Translate phrases to algebraic expressions.

Objective a
Evaluate algebraic expressions by substitution.

Algebraic Expressions



Example A

Evaluate x + y for x = 38 and y = 62.
Solution
We substitute 38 for x and 62 for y.
x + y = 38 + 62 = 100

Example B



Example C



Objective b
Translate phrases to algebraic expressions.

Translating to Algebraic Expressions



Example D

Translate each phrase to an algebraic expression.
Phrase
a) 9 more than y
b) 7 less than x
c) the product of 3 and twice w

Solution
Algebraic Expression
a) y + 9
b) x - 7
c) 3•2w or 2w • 3

Example E