Adding and Subtracting Linear Expressions
1. We want to add (2x+3) + (x+1). Group together 2 x’s and 3 1’s to represent 2x+3. Leave a
little space and then represent x + 1 similarly. See the picture below.
2. To add these expressions count how many total x’s there are and how many total 1’s there are.
# of x’s = ____
# of 1’s = ____
3. Write an expression representing the sum of (2x+3) and (x+1).
(2x+3) + (x+1) = _________________
4. Use your tiles to add the following and write the solution:
a. (3x+2) + (2x+4) = _________________
b. (4x+5) + (2x+3) = _________________
c. (5x+7) + (4x+1) = _________________
5. Now, we want to subtract (2x+3) - (x+1). Start with the same set up but this time take away
from the first group the number of x’s and 1’s in the second.
We are left with 1 x and 2 1’s, or x+2.
6. Use your tiles to subtract the following and write the solution:
a. (5x+2) - (2x+1) = _________________
b. (3x+6) - (x+6) = _________________
c. (4x+8) - (4x+4) = _________________
7. Make up two examples with addition and two examples with subtraction. Write out the two
expressions you added or subtracted and what the solution is.