# How do you define a variable and write an expression for each phrase: the total of four times a number and twice the difference between the number and four?

Mar 25, 2018

first phrase: $4 x$
seconds phrase: $2 \left(x - 4\right)$

#### Explanation:

Let us define the variable 'the number' as $x$.
$x$ can be any number, which is why it is called a variable.

The first phrase, 'four times a number', is expressed as $4 x$. Literally, $4 \cdot x$, or four times $x$.

The second phrase is harder, 'the difference between the number and 4' is simply our number subtract 4: $x - 4$, but this is doubled, which becomes $2 \left(x - 4\right)$

Hope this helps!