Chapter 9 - XYZ Custom Plus
Chapter 9 - XYZ Custom Plus
Chapter 9 - XYZ Custom Plus
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<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