Combining Like Terms

Students will identify like terms and combine like terms to solve problems.

Combine Like Fruits

4 apples + 3 bananas + 3 apples + 2 bananas 4 + 3 apples 7 apples 3 + 2 bananas 5 bananas

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.

Examples

Which terms are the “same” or

LIKE TERMS

?

5x, 8y, 9z, 10, x 2 , 12x, 14z, 7, 3x 2 5x 8y 9z 10 and ?

7

x

2

and ?

2

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

4x + 9x

13x

4x + 8y + 10x

14x + 8y

Let’s try it!

-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 -20 – 6y 5. 8(2x – 3y) + 4(y – 3x) 16x – 24y + 4y – 12x 4x – 20y

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