1. Warm Up
Problem of the Day
Lesson Presentation
Lesson Quizzes

2. Warm Up
Evaluate each expression for y = 3.
1. 3y + y
2. 7y
3. 10y – 4y
4. 9y
5. y + 5y + 6y 12 21 18 27 36

3. Problem of the Day
Emilia saved nickels, dimes, and quarters in a jar. She had as many quarters as dimes, but twice as many nickels as dimes. If the jar had 844 coins, how much money had she saved?
$94.95

4. Learn to simplify algebraic expressions.

5. Vocabulary
term
coefficient

6. In the expression 7x + 9y + 15, 7x, 9y, and 15 are called terms
In the expression 7x + 9y + 15, 7x, 9y, and 15 are called terms. A term can be a number, a variable, or a product of numbers and variables. Terms in an expression are separated by + and –. x 3
7x – 3y y +
term
term
term
term
term
In the term 7x, 7 is called the coefficient. A coefficient is a number that is multiplied by a variable in an algebraic expression. A variable by itself, like y, has a coefficient of 1. So y = 1y.
Coefficient
Variable 7 x

7. Like terms are terms with the same variables raised to the same exponents. The coefficients do not have to be the same. Constants, like 5, , and 3.2, are also like terms. 1 2
Like Terms
Unlike Terms w 7
3x and 2x
w and
5 and 1.8
5x2 and 2x
6a and 6b
3.2 and n
Only one term
contains a
variable
The exponents
are different.
The variables
are different

8. Additional Example 1: Identifying Like Terms
Identify like terms in the list.
3t 5w2 7t 9v w2 8v
Look for like variables with like powers.
3t 5w2 7t 9v w2 8v
Like terms: 3t and 7t 5w2 and 4w2 9v and 8v
Use different shapes or colors to indicate sets of like terms.
Helpful Hint

9. Check It Out: Example 1
Identify like terms in the list.
2x 4y3 8x 5z y3 8z
Look for like variables with like powers.
2x 4y3 8x 5z y3 8z
Like terms: 2x and 8x 4y3 and 5y3 5z and 8z

10. + = Combining like terms is like grouping similar objects. x x x x x x
To combine like terms that have variables, add or
subtract the coefficients.

11. Additional Example 2: Simplifying Algebraic Expressions
Simplify. Justify your steps using the Commutative, Associative, and Distributive Properties when necessary.
A. 6t – 4t
6t – 4t
6t and 4t are like terms. 2t
Subtract the coefficients.
B. 45x – 37y + 87
In this expression, there are no like terms
to combine.

12. Additional Example 2: Simplifying Algebraic Expressions
Simplify. Justify your steps using the Commutative, Associative, and Distributive Properties when necessary.
C. 3a2 + 5b + 11b2 – 4b + 2a2 – 6
Identify like
terms.
3a2 + 5b + 11b2 – 4b + 2a2 – 6
Group like
terms.
(3a2 + 2a2) + (5b – 4b) + 11b2 – 6
5a2 + b + 11b2 – 6
Add or subtract
the coefficients.

13. Distributive Property.
Check It Out: Example 2
Simplify. Justify your steps using the Commutative, Associative, and Distributive Properties when necessary.
A. 5y + 3y
5y + 3y
5y and 3y are like terms. 8y
Add the coefficients.
B. 2(x2 – 13x) + 6
2x – 26x + 6 2
Distributive Property.
There are no like terms to combine.

14. Check It Out: Example 2
Simplify. Justify your steps using the Commutative, Associative, and Distributive Properties when necessary.
C. 4x2 + 4y + 3x2 – 4y + 2x2 + 5
4x2 + 4y + 3x2 – 4y + 2x2 + 5
Identify like
terms.
(4x2 + 3x2 + 2x2)+ (4y – 4y) + 5
Group like
terms.
Add or subtract
the coefficients.
9x2 + 5

15. Additional Example 3: Geometry Application
Write an expression for the perimeter of the triangle. Then simplify the expression.
2x + 3
3x + 2 x
Write an expression using
the side lengths.
2x x x
(x + 3x + 2x) + (2 + 3)
Identify and group like terms.
6x + 5
Add the coefficients.

16. Write an expression using the side lengths. x + 2x + 1 + 2x + 1
Check It Out: Example 3
Write an expression for the perimeter of the triangle. Then simplify the expression.
2x + 1
2x + 1 x
Write an expression using
the side lengths.
x + 2x x + 1
(x + 2x + 2x) + (1 + 1)
Identify and group like terms.
5x + 2
Add the coefficients.

17. Lesson Quizzes
Standard Lesson Quiz
Lesson Quiz for Student Response Systems

18. Lesson Quiz: Part I
Identify like terms in the list.
1. 3n2 5n 2n3 8n
2. a5 2a2 a3 3a 4a2
Simplify. Justify your steps using the Commutative, Associative, and Distributive Properties when necessary.
3. 4a + 3b + 2a
4. x2 + 2y + 8x2
5n, 8n
2a2, 4a2
6a + 3b
9x2 + 2y

19. Lesson Quiz: Part II
5. Write an expression for the perimeter of the given figure.
2x + 3y
x + y
x + y
2x + 3y
6x + 8y

20. Lesson Quiz for Student Response Systems
1. Identify the like terms in the list.
6a, 5a2, 2a, 6a3, 7a
A. 6a and 2a
B. 6a, 5a2, and 6a3
C. 6a, 2a, and 7a
D. 5a2 and 6a3

21. Lesson Quiz for Student Response Systems
2. Identify the like terms in the list.
16y6, 2y5, 4y2, 10y, 16y2
A. 16y6 and 16y2
B. 4y2 and 16y2
C. 16y6 and 2y2
D. 2y5 and 10y

22. Lesson Quiz for Student Response Systems
3. Simplify 5x + 2y + 7x. Justify your steps using the Commutative, Associative, and Distributive Properties when necessary.
A. 5x + 2y + 7x = 5x + 7x + 2y Associative Property
= (5x + 7x) + 2y Commutative Property
= 12x + 2y Add the coefficients.
B. 5x + 2y + 7x = 5x + 7x + 2y Commutative Property
= (5x + 7x) + 2y Associative Property

23. Lesson Quiz for Student Response Systems
4. Simplify 5x2 + 3x + 8x2. Justify your steps using the Commutative, Associative, and Distributive Properties when necessary.
A. 5x2 + 3x + 8x2 = 5x2 + 8x2 + 3x Commutative Property
= (5x2 + 8x2) + 3x Associative Property
= 13x2 + 3x Add the coefficients.
B. 5x2 + 3x + 8x2 = 3x + 5x2 + 8x2 Associative Property
= (3x + 5x2) + 8x2 Commutative Property
= 8x + 8x Add the coefficients.

24. Lesson Quiz for Student Response Systems
5. Identify an expression for the perimeter of the given figure.
A. (4x + 5y)(x + 2y) C. 10x + 14y
B D. 5x + 7y
4x + 5y
x + 2y