# How do i write 4 less than twice a number as an algebraic expression?

Mar 26, 2018

$2 n - 4$

#### Explanation:

We'll refer to our number as $n .$

The problem says we have twice the number. This would mean the number is multiplied by two, or $2 n .$

Moreover, we want four less than twice the number. This entails subtracting $4$ from $2 n : 2 n - 4$

In general, when translating from words into expressions:

"less than" implies subtracting.

"twice/three times/four times/ $x$ times" implies multiplying.

"half of/quarter of/tenth of/ $x t h$ of" implies dividing.

Mar 27, 2018

$2 n - 4$

#### Explanation:

We need to rearrange the word problem a little. When they are saying "4 less than twice a number", that's the same as saying "twice a number minus 4". When you are asking for less than something, that indicates subtraction!

We'll abbreviate number to $n$.

$\stackrel{2 n}{\overbrace{\text{twice a number" " " stackrel(-)overbrace"minus" " " stackrel(4)overbrace"4}}}$

$2 n - 4$

2. Abbreviate words into something that you can remember. Number starts with $n$, so that is a good way to remember what it represents.