Question

How do you define a variable and write an algebraic expression for the phrase: 12 less than a number?

Answer 1

The expression is `x-12`.

Explanation:

`12` less than a number means to subtract `12` from that number.

So, `12` less than `20` is `8`, because is `20-12`, `12` less than `12` is `0`, because it's `12-12`, and so on.

But since you don't know which number you need to subtract from, it's a variable, and you can call it as you like, usually `x`.

So, using the variable we can write an expression that holds for any number, and which always means "take `12` away from my number". If your number is `x`, the expression would be `x-12`