# What is Algebraic Expression

Algebraic expression is a bunch of numbers (constants), operations and variables.

Unlike number expressions, algebraic expressions can contain variables.

Following is example of algebraic expression:

${\color{green}{{{x}}}}{\color{blue}{{\times}}}{\color{red}{{{2}}}}{\color{blue}{{+}}}{\color{red}{{{3}}}}{\color{blue}{{-}}}{\color{green}{{{x}}}}{\color{blue}{{\times}}}{\color{green}{{{y}}}}{\color{blue}{{+}}}{{\color{green}{{{x}}}}}^{{\color{red}{{{2}}}}}{\color{blue}{{+}}}{{\left({\color{red}{{{5}}}}{\color{blue}{{-}}}{\color{green}{{{x}}}}\right)}}^{{{\color{green}{{{y}}}}}}$

Constants are red, variables are green, operations are blue.

Sometimes, we can discard multiplication and write ${x}{y}$ instead of ${x}\times{y}$. This is possible to do, if you really sure that others will not have to guess, what you wrote.

For example, you can write ${2}{x}$ instead of ${2}\cdot{x}$.

However, you can't write ${123}$ instead of ${12}\times{3}$, because you mean ${12}\times{3}={36}$, but others see $123$.