Combining Like Terms
Students will identify like
terms and combine like terms
to solve problems.
Combine Like Fruits
4 apples
+
3 bananas
4 + 3 apples
7 apples
+
3 apples
3 + 2 bananas
5 bananas
+ 2 bananas
Examples
Which terms are the “same” or LIKE TERMS?
5x, 8y, 9z, 10, x2, 12x, 14z, 7, 3x2
5x and ?
8y and ?
9z and ?
10 and ?
x2 and ?
Only combine terms that are the
same!!
• What’s the “SAME” or “Like Terms” mean?
– The variables (letters) MUST be the same with
the SAME POWERS.
– You can also combine numbers that have no
variables.
Combining Terms
To combine Like Terms, add or subtract the
coefficients (numbers in front of the
variables)… The variable stays the same.
Example:
5x + 9x
THINK: 5 + 9 = 14
and bring down the x.
14x
Let’s try it!
4x + 9x
4x + 8y + 10x
-7y + 9y
-8y + (-4y)
5 + 8x + 7y + 10
Let’s try it!
4x + 9x
13x
4x + 8y + 10x
14x + 8y
-7y + 9y
2y
-8y + (-4y)
-12y
5 + 8x + 7y + 10
8x + 7y + 15
More Problems:
1. 4x + 5y – 2x + 3y
2x + 8y
2. 5(x + y) + 2(x + y)
Use the distributive property first.
5x + 5y + 2x + 2y
7x + 7y
3. 3 + 5x – 4y + 2y – 8x
3 – 3x – 2y
Problems Cont.
4. (-13) + (-2y) + (-7) – 4y
5. 16x – 3y + 4y – 3x)
6. 3ab + 5a – 7ab + 14a + 8ab
Summary
Combine LIKE TERMS only if they have
exactly the same letters with the same
powers.
Combine Like Terms by adding or
subtracting the coefficients (numbers)
Constants (terms without variables) can also
be combined by adding or subtracting.
END