Page 107 - Math Course 1 (Book 1)

Open Sentences

Mo. 3

Lesson 4

Solution
KEY CONCEPTS:
1. Identify and solve open sentences. A value for the variable that makes an equation true
2. Translate verbal sentences into equations.
is called a solution.

For x + 7 = 19, the solution is 12.
MO. 3 - L4a

Solving Open Sentences Solving the Equation

The process of f nding a solution is called solving
the equation.
Vocabulary A-Z
Let us learn some vocabulary Find the solution of 12 - m = 8. Is it 2, 4, or 7?

Replace m with each value. Replacing m with 4
makes the open sentence true.

Therefore, the solution of 12 - m = 8 is 4.
Equation

A mathematical sentence that contains an equals
sign (=) is called an equation.

5 + 9 = 14 2 (6) - 3 = 9 Let’s Begin
x + 7 = 19 2m - 1 =13

Solve an Equation

Open Sentence
Example
An equation that contains a variable is an open
sentence. An open sentence is neither true nor false.
Find the solution of 44 + p = 53. Is it 11, 9, or 7?
Replace p with each value.
x + 7 = 19
Value for P 44 + p = 53 True of False?
11 + 7 = 19 Replace x with 11. ?
11 44 + 11 = 33 false
18 = 19 false ?
9 44 + 9 = 53 true
When x = 11, this sentence is false. ?
7 44 + 7 = 53 false
x + 7 = 19
Therefore, the solution of
Answer
12 + 7 = 19 Replace x with 12. 44 + p is 9.

19 = 19 true

When x = 12, this sentence is true.

99