### Algebra: Variables

### Substitution

Substitution

If a variable occurs in an expression, you can enter any number for that variable. In other words: replace every occurence of that variable in the expression by a number. This process is called |
Calculate #\blue{x}^2+\blue{x}# for #\blue{x}=\green{3}#: \[{\blue{x}^2+\blue{x}=}{\green{3}^2+\green{3}}{=12}\] |

#{{1}\over{3}}#

#\begin{array}{rcl}

\displaystyle {{x}\over{-x^2-x+5}} &=& \displaystyle{{1}\over{-1^2-1+5}} \\

&&\blue{\text{\(x\) replaced with \(1\)}}\\

&=& \displaystyle {{1}\over{3}} \\

&&\blue{\text{calculated}}\\

\end{array}#

Unlock full access

Teacher access

Request a demo account. We will help you get started with our digital learning environment.

Student access

Is your university not a partner?
Get access to our courses via

Or visit omptest.org if jou are taking an OMPT exam.

**Pass Your Math**independent of your university. See pricing and more.Or visit omptest.org if jou are taking an OMPT exam.