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

1 Answer
Oct 14, 2015

Answer:

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#