1. Adding and Subtracting Expressions
Section 2.6

2. Essential Question How can the distributive property
be used to simplify algebraic
Expressions?

3. Vocabulary
Expression: Combining numbers, variables and addition and subtraction symbols. Does not contain an equal sign.
( 3x + 4 ) + ( 5x + 2 )
Constant: means the same, as fixed. That is, not changing or moving.
Coefficient: number sitting before the variable.
Term: Parts of an expression separated by
+ or – signs
Like Terms: Terms that contain the SAME form of variable(s)
Variables: letter representing a quantity.

5. 4x 8x2 unlike Different types of variables are unlike terms.
To be like terms, the variable part
is what has to be the same,
not the numbers.
unlike

6. 2xy - x2y 1 unlike Different types of variables are unlike terms.
The variable part is what has
to be the same, not the numbers.
unlike

7. 3xy -9xy LIKE These are like terms even though
they contain both an x and a y.
3xy
-9xy
LIKE

8. These are also like terms.xy 1 1 yx
LIKE
We write variables in
alphabetical order.

9. xy yx LIKE 5 -3 Even if we put numbers in front
(coefficients) of each variable,
they are still like terms. xy yx
LIKE 5 -3

10. Distribute Property: To multiply out the parts of an expression
( 5a + 11 ) – ( 12a – 24 )
( 3x + 4 ) + ( 5x + 2 )
Simplified: when all like terms have been combined and all parentheses have been removed.

11. Examples Distribute + sign
2. ( 8x – 2y ) + ( 5x + 6y )
1. ( 3x + 4 ) + ( 2x – 1 )
3. ( 3x + 2 ) + ( 4x + 3 )
4. ( 2b – 3c ) + ( 10b + 4c )
5. ( 3x + 6 ) + ( -4x + 5 )
6. ( 4x – 3y ) + ( 2x + 2y )

12. Practice Copy problem Show Combine like terms Simplify
Page 92 numbers 25, 26, 28, 30, 31
Page 743 Lesson 2.6 numbers 34, 35
Copy problem
Show Combine like terms
Simplify

13. Math Starter
( 3d + 1 ) + ( -4d – 3 ) + ( 5d – 6 )

14. Homework answers 7r + 6r + 2s + 3s 9k + 11k + 2j – 2j 20K
-1x + 2x + 2y + 3y
1x + 5y
4m – 3m – 2n – 4n
1m – 6n
r +17r -7 -6
20r - 13

15. Examples Distribute - sign
1. ( 4b – 2 ) – ( 5b – 3 )
2. ( 5a + 3b ) – ( 2a + 5b )
3. ( - 4m + 3 ) – ( - 6m + 3 )
4. ( 3m + 17n ) – ( 5m + 15n)
5. ( 2x + 3 ) – ( 4x – 1 )

16. Practice Book page 92 numbers 27, 29, 32, 34, 36, 38 Copy problem
Show Combine like terms
Simplify
More practice page 743 lesson 2.6

17. Homework answers 29. 5x + 7 -2x + 7 27. 2a – 1 + 5a + 5
- 4x – 2y -4x – 2y
-4x – 4x – 2y – 2y
-8x – 4y
-7f + 2 – 6f – 3
-7f – 6f + 2 – 3
-13f - 1

18. - 5x + 2y- 3x – 2y
-5x – 3x + 2y – 2y
- 8x
2q q – 5 + 6q – 7
2q + 4q + 6q + 3 – 5 – 7
12q - 9