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CHAPTER 2 MATHQUEST�PART 1

EXPRESSIONS AND EQUATIONS

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CHAPTER OBJECTIVES

  • Use algebraic expressions to describe relationships
  • Use mental math to estimate solutions to equations
  • Use addition, subtraction, multiplication, and division to solve equations
  • Write equations to solve problems

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SECTION 2-1

VARIABLES AND EXPRESSIONS

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Section 2-1-Variables and Expressions

​

  • Watch the following video: Variables/Expressions Video

(You can stop at 4:40)

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Section 2-1-Variables and Expressions

VOCABULARY

  • numerical expression-mathematical phrase with only numbers and operation symbols
  • variable-a letter that stands for a number
  • algebraic expression-mathematical phrase that uses variables, numbers, and operation symbols
  • evaluate-replace, or substitute, any known variables with a number and then follow the order of operations
  • substitution-putting or replacing the known variable where the variables are

​

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Section 2-1-Variables and Expressions

EXAMPLES

Evaluate each expression.

  1. p + 8 for p = 6
  2. 3r - 2 for r = 65
  3. 11t - 6v for t = 9 and v = 4

Complete the table

x

7x

2

​

4

​

6

​

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SECTION 2-2

WRITING ALGEBRAIC EXPRESSIONS

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Section 2-2-Writing Algebraic Expressions

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  • Watch the following video:

Expressions

​

  • Watch the following video:

Writing Algebraic Expressions

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Section 2-2-Writing Algebraic Expressions

EXAMPLES

Write an expression for each word phrase.

  1. 34 less than k
  2. 13 minus d
  3. d more than 50

Write an expression to describe the relationship in the table.

​

n

​

42

7

54

9

72

12

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SECTION 2-3

USING NUMBER SENSE TO SOLVE ONE-STEP EQUATIONS

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Section 2-3-Using Number Sense to Solve One-Step Equations

  • Watch the following video:

Equation Guess/Check�

  • Watch the following video:

One Step Solving

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Section 2-3-Using Number Sense to Solve One-Step Equations

VOCABULARY

  • equation-mathematical sentence with an equal sign
  • open sentence-an equation with one or more variables
  • solution-any value or values that make an equation or inequality true

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Section 2-3-Using Number Sense to Solve One-Step Equations

EXAMPLES

Solve each equation.

  1. x + 5 = 7
  2. 4x = 32
  3. 25 = p - 6