1. Warm-Up
Combine Like Terms:
6x + 2y - 3x + 4y
-3z + 4x -5y + 2z

2. COMBINING LIKE TERMS

3. LIKE TERMS
Terms that have the same variable part or “last name” but differ only in their numerical coefficients
“Last Name”
Part
-4x2y
7x2y
coefficient
coefficient

4. COMBINING LIKE TERMS -2ab + 4a + 7ab – 6a
You can only add or subtract terms that have exactly the same variable part or “last name.”
-2ab + 4a + 7ab – 6a

5. -2ab + 4a + 7ab – 6a -2ab + 7ab = 5ab 4a – 6a = -2a 5ab – 2a
COMBINE LIKE TERMS
Make sure you take the sign to the left of each term when you combine them.
-2ab + 7ab =
5ab
4a – 6a =
-2a
5ab – 2a

6. NOW YOU TRY IT! -9 – 4x2 + 6x – y – 8x + 3y -4x2 – 2x + 2y - 9 -4x2

7. TEST YOURSELF 1) 7s – 9s + 7r – 10r 2) –5m – 3m2 + 8 – 6m2
3) –5 + 11a – 4b –2a + b
4) 3c – 6d d – 4c
5) 2 + 5x – 8 – 7x – 9 + y

8. ANSWERS 1) –3r – 2s 2) –9m2 – 5m + 8 3) 9a – 3b - 5 4) –c + 6
5) –2x + y - 15

9. REMEMBER. . .
You can only add or subtract “like terms.” Terms that have the same variable part or “last name.”
When combining like terms, remember to take the sign to the left of each term.

10. Did you hear the one about the acupuncture?
It was a jab well done.
I 8. A 15. O
2. T 9. B 16. N
3. W W 17. E
4. A E
5. S L
6. A (10g) 13. L
7. J D