1. This document provides examples of evaluating algebraic expressions by substituting values for variables and modeling expressions. 2. It includes examples of writing expressions for word problems and using formulas by replacing variables with given values and simplifying. 3. Tables are included that require copying and completing expressions for given variable values.

1. Standards Practice NS 1.2
A Practice by Example Model each expression.
Example 1 1. 3 x 5 Guided Practice
(page 8) This exercise has been
started for you!
Use for x. Use for 1.
2. x 3 3. 8 4. x 4 5. 4 2x
6. 3 x 1 7. 5x 8. 1 x 9. 2 x 6
Example 2 Evaluate each expression.
(page 9)
10. 24 d for d 3 Guided Practice
This exercise has been
24 d 24 3 started for you!
11. p 8 for p 5 12. 8 b 12 for b 2
For: Examples 1–3
Visit: PHSchool.com 13. 18 3 y for y 3 14. ( g 9) 3 for g 6
Web Code: axe-0102
15. 21 (t 2) for t 9 16. 10 m 5 for m 1.5
Example 3 17. The rental fee for a bicycle is $5, plus $2
Hour Rental Fee
(page 9) for each hour h the bike is rented. The
h 5 2h
expression for the total cost is 5 2h. Copy
and complete the table for the given number 1 ■
of hours. 2 ■
3 ■
Copy and complete each table.
18. x x 6 19. x 7x 20. x 100 x
1 7 2 20
4 4 35
7 6 50
B Apply Your Skills 21. Guided Problem Solving The formula P 2 2 w gives the
distance around a rectangle with length and width w. Find P for a
rectangle with length 7 cm and width 4 cm.
• Replace each variable in the formula with the given values.
• Use the order of operations to simplify the expression.
22. A dog walker charges $10 to walk a large dog and $6 to walk a small
dog. She uses 10 d 6s to calculate her earnings, where d is the
number of large dogs and s is the number of small dogs. How much
does she earn for walking each group?
a. 4 large and 2 small dogs b. 6 small dogs
10 Chapter 1 Variables and Algebraic Expressions 1-2 Algebraic Expressions