22.02.2014 Views

Chapter 9 - XYZ Custom Plus

Chapter 9 - XYZ Custom Plus

Chapter 9 - XYZ Custom Plus

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

<strong>Chapter</strong> 9 Summary<br />

Combining Similar Terms [9.1]<br />

Two terms are similar terms if they have the same variable part. The expressions<br />

7x and 2x are similar because the variable part in each is the same. Similar terms<br />

are combined by using the distributive property.<br />

Examples<br />

1. 7x 1 2x 5 (7 1 2)x<br />

5 9x<br />

Finding the Value of an Algebraic Expression [9.1]<br />

An algebraic expression is a mathematical expression that contains numbers and<br />

variables. Expressions that contain a variable will take on different values depending<br />

on the value of the variable.<br />

2. When x 5 5, the expression<br />

2x 1 7 becomes<br />

2(5) 1 7 5 10 1 7 5 17<br />

The Solution to an Equation [9.2]<br />

A solution to an equation is a number that, when used in place of the variable,<br />

makes the equation a true statement.<br />

The Addition Property of Equality [9.2]<br />

Let A, B, and C represent algebraic expressions.<br />

If<br />

A 5 B<br />

then A 1 C 5 B 1 C<br />

In words: Adding the same quantity to both sides of an equation will not change<br />

the solution.<br />

3. We solve x 2 4 5 9 by adding 4<br />

to each side.<br />

x 2 4 5 9<br />

x 2 4 1 4 5 9 1 4<br />

x 1 0 5 13<br />

x 5 13<br />

The Multiplication Property of Equality [9.3]<br />

Let A, B, and C represent algebraic expressions, with C not equal to 0.<br />

If<br />

A 5 B<br />

then AC 5 BC<br />

In words: Multiplying both sides of an equation by the same nonzero number will<br />

not change the solution to the equation. This property holds for division as well.<br />

4. Solve } 1 }x 5 5.<br />

3<br />

} 1 3 }x 5 5<br />

3 ? } 1 3 }x 5 3 ? 5<br />

x 5 15<br />

Steps Used to Solve a Linear Equation in One Variable [9.4]<br />

Step 1 Simplify each side of the equation.<br />

Step 2 Use the addition property of equality to get all variable terms on one side<br />

and all constant terms on the other side.<br />

5. 2(x 2 4) 1 5 5 211<br />

2x 2 8 1 5 5 211<br />

2x 2 3 5 211<br />

2x 2 3 1 3 5 211 1 3<br />

2x 5 28<br />

} 2 x<br />

} 5 } 2 8<br />

}<br />

2 2<br />

<strong>Chapter</strong> 9<br />

Summary<br />

x 5 24<br />

569

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!