Combining Like Terms Notes and Practice

Combining Like Terms Notes and Practice

In order to solve equations or simplify expressions, you may need to combine "like terms".

For example, say you have the expression 3x + 5x + 7y + 9x - 4y

Example: 3x + 5x + 7y + 9x - 4y

This expression looks a bit confusing, but we can combine common terms to make it much simpler.
To be a common term, the term must have the same variable and the same exponents.

Example: 
3x + 5x + 7y + 9x - 4y

This expression looks a bit confusing, but we can combine common terms to make it much simpler.

To be a common term, the term must have the same variable and the same exponents.

Example: 3x + 5x + 7y + 9x - 4y

• When you combine like terms, be sure to use the + or - that is in front of the coefficient, or number in before the letter.

• So in this case, we will add the 3, 5 and 9 that is in front of the x terms. Then we will subtract 7 and 4 that is in front of the y terms.

• 3x + 5x + 7y + 9x - 4y = 17x + 3y

Example: a + a + a + a

There is a understood 1 in front of a variable if it is by itself.
So, in this case it would be like adding 1 + 1 + 1 + 1
Your answer would be 5a

Example: 3x + 3 - x + 5

- 3x and x can be put together because they have the same variable 
- 3 and 5 can be put together because they are both constants
- So, you would do 3x - x =  2x  and   3 + 5 = 8
- Answer: 2x + 8

Multiple Choice

a + a + a + a

• 4a

• a

• 4

• 1

Multiple Choice

2x + 4x + 3

• 2x + 3

• 6x + 3

• 4x + 3

• 9x

Multiple Choice

2c + 6 + 5c - 2

• 11

• 8c + 3

• 7c + 4

• 7c + 8