When you look in a dictionary, you can find different definitions about equations. In order to explain in the easiest possible way, you can say that an equation:
- is an equality between two mathematical expression, which are called the left hand side and the right hand side.
- Contains one or several unknowns. If it contains an unknown, we usually use the letter x.
5x + 2 =
The letter x is an unknown and 5x + 2 is equal to 18, it is an equality.