Simplifying like terms
Like terms are those that include the same letters. Therefore 3x, 7x, − 4x are all like terms. However, 3x, 7y, − 4y2 are not like term. To simplify an expression like terms can be added or subtracted, this is done by putting all like terms together, before calculating
Example 1. Simplify 3x + 7x + 2x
Example 2. Simplify 19a + 7b − 4a + b
Example 3. Simplify 10y2 − 17y − 4y2 + 5y
Example 4. Simplify xyz + 2yxz + 3yzx + 4zxy + 5zyx
Example 5. Simplify 4x − 3y
These are all like terms
| 3x + 7x + 2x | = | 12x |
Rearrange by putting all like terms together. Note b = 1b
19a + 7b − 4a + b
| = | 19a − 4a + 7b + b | ||
| = | 15a + 8b |
Rearrange by putting all like terms together.
10y2 − 17y − 4y2 + 5y
| = | 10y2 − 4y2 − 17y + 5y | ||
| = | 6y2 − 12y |
The terms yxz, yzx, zxy and zyx are all the same as the term xyz
xyz + 2yxz + 3yzx + 4zxy + 5zyx
| = | 15xyz |
Cannot be simplified because they are different terms
to: 
