Lesson 1-5 Pages 28-32

Variables and Equations

What you will learn!1. How to identify and solve open sentences.

2. How to translate verbal sentences into equations.

EquationEquation

Open sentenceOpen sentence

SolutionSolution

Solving the equationSolving the equation

What you really need to know!

An equation that contains a variable is called an open sentence.

A value that makes the sentence true is called a solution.

SymmetricSymmetric If one quantity equals a If one quantity equals a second quantity, then second quantity, then the second quantity also the second quantity also equals the first.equals the first.

TransitiveTransitive If one quantity equals a If one quantity equals a second quantity and the second quantity and the second quantity equals second quantity equals a third quantity, then the a third quantity, then the first equals the third.first equals the third.

Properties of Equality:

Balance Example!

Example 1:

Find the solution of:

44 + p = 53.

Is it 11, 9, or 7?

p is 9 ; p = 9

Example 2:

Which value is the solution of

4x – 1 = 11?

A 5 B 4 C 3 D 2

C 3

Example 3:

Solve the equation mentally.

7x = 56

x = 8

Example 4:

Solve the equation mentally.

x – 15 = 40

x = 55

Example 5:

Name the property shown by the statement.

If 3x + 1 = 10, then 10 = 3x + 1.

Symmetric

Example 6:

Name the property shown by the statement.

If z + 6 = 8 and 8 = 2 + 6,

the z + 6 = 2 + 6.

Transitive

Example 7:

Define a variable. Then write an equation and solve.

The quotient of a number and four is nine.

n = 36n ÷ 4 = 9

Page 30

Guided Practice

#’s 3-13Link to Pre-Made Lesson

Pages 28-30 with someone at home

and study examples!

Read:

Homework: Pages 31-32

14-46 even

48-51, 54-55,

58-59, 61-73Lesson Check 1-5

Page

725

Lesson 1-5

Lesson Check 1-5