Lesson 2.7
Combining Like Terms
Mr. Beltz & Mr. Sparks
Goal

Simplify an expression by combining
like terms.
Vocabulary

Like Terms: are terms in an expression that have the
same variable raised to the same power.

Examples
 8x and 3x
Yes
2
2
 x and x
Yes
 x and 3x
Yes, why?
2
3
 1x and x
No, why not?
Practice: Identify the LT

-5x2 – x + 8 + 6x – 10


-x and 6x, 8 and -10
-3x2 + 2x + x2 – 4 + 7x

-3x2 and x2, 2x and 7x
*Remember the signs stay with the number to the right!
Simplifying Expressions

8x + 3x =


8x + 3x = 11x
2y2 + 7y2 – y2 + 2=



2y2 + 7y2 = 9y2
9y2– 1y2 = 8y2
8y2 + 2= 8y2 + 2
Student Practice

P. 108 # 3-5


Show original problem
Show all work/steps
Distributing and Simplifying
Example:
5( x + 1 ) + 2( 4 － x )
5x + 5 + 2•4 － 2•x
5x + 5 + 8 － 2x
5x － 2x + 5 + 8
3x + 13
Example:
1 － 4( 1 － 2x)
1 + (－4)( 1 + -2x)
1 + (－4)(1) + (-4)(-2x)
1 + (-4) + 8x
-3 + 8x
Try These:

Page 108 # 6, 7, 8

Homework:

Page 110 #16 – 38 even

Day 2 – Page 110 # 15- 37 odd