Chapter 9 - XYZ Custom Plus
Chapter 9 - XYZ Custom Plus
Chapter 9 - XYZ Custom Plus
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
The Distributive Property<br />
and Algebraic Expressions<br />
We recall that the distributive property from Section 1.5 can be used to find the<br />
area of a rectangle using two different methods.<br />
x 3<br />
4<br />
x 3<br />
Area 5 4(x ) 1 4(3) Area 5 4(x 1 3)<br />
5 4x 1 12 5 4x 1 12<br />
Since the areas are equal, the equation 4(x 1 3) 5 4(x ) 1 4(3) is a true statement.<br />
4<br />
9.1<br />
Objectives<br />
A Apply the distributive property to<br />
an expression.<br />
B Combine similar terms.<br />
C Find the value of an algebraic<br />
expression.<br />
D Solve applications involving<br />
complementary and supplementary<br />
angles.<br />
Examples now playing at<br />
MathTV.com/books<br />
A<br />
The Distributive Property<br />
Example 1<br />
Apply the distributive property to the expression:<br />
5(x 1 3)<br />
Practice Problems<br />
1. Apply the distributive property<br />
to the expression 6(x 1 4).<br />
Solution<br />
Distributing the 5 over x and 3, we have<br />
5(x 1 3) 5 5(x) 1 5(3) Distributive property<br />
5 5x 1 15 Multiplication<br />
Remember, 5x means “5 times x.”<br />
The distributive property can be applied to more complicated expressions involving<br />
negative numbers.<br />
Example 2<br />
Multiply: 24(3x 1 5)<br />
2. Multiply: 23(2x 1 4)<br />
Solution<br />
Multiplying both the 3x and the 5 by 24, we have<br />
24(3x 1 5) 5 24(3x) 1 (24)5 Distributive property<br />
5 212x 1 (220) Multiplication<br />
5 212x 2 20 Definition of subtraction<br />
Notice, first of all, that when we apply the distributive property here, we multiply<br />
through by 24. It is important to include the sign with the number when we use<br />
the distributive property. Second, when we multiply 24 and 3x, the result is 212x<br />
because<br />
24(3x) 5 (24 ? 3)x Associative property<br />
5 212x Multiplication<br />
Answers<br />
1. 6x 1 24 2. 26x 2 12<br />
9.1 The Distributive Property and Algebraic Expressions<br />
511