Add and subtract expressions

1. QUESTION:
How can we write an
expression denoted by these 2
tiles together?
𝐱 𝟐
1

2. AIM:
Today we will add
and subtract
algebraic
expressions using
algebra tiles

3. TASK:
1. Represent the expressions in each
set using algebra tiles.
2. Add the first set of tiles and
subtract the second set.
Set 1: 𝒙 𝟐
+ 𝒙 + 𝟏 and −𝟑𝒙 − 𝟐
Set 2: 𝒙 + 𝟐 and 𝒙 + 𝟏

4. The Algebra Tile
= 1= x= 𝐱 𝟐
= –1= –x= –𝐱 𝟐

5. QUESTION:
What expressions did you get?
Which tiles did you add or subtract?
What did you get on combining a red and
blue tile of the same shape?
How did you subtract using the algebra tiles?

6. How to add or subtract
expressions?
• Add or subtract only like terms in
the expression.
• For subtraction, the signs of the
terms are handled the same way as
for integers and the signs of the
terms being subtracted are changed.

7. EXAMPLE:
Maria has three more four times the
number of pencils Ryan has. She loses
two more than three times the
number of pencils Ryan has.
How many pencils is she left with?

8. EXAMPLE:
(2x + 5) + (6x – 2)
𝟑𝒙 𝟐
+ 𝟕𝒚 + 𝟒𝒙 𝟐
− 𝟖𝒚 + 𝟏𝟐
Subtract 𝒙 𝟐
− 𝟕𝒙 − 𝟏 from
𝟑𝒙 𝟐
+ 𝟓𝒙 + 𝟒 .

9. CLASSWORK:
FINISH S3
from the XSEED
Workbook, page 24.

10. HOMEWORK:
Complete
Practice Questions
1 – 5
from the XSEED
Content Book, page
110 – 111.