Question

How do you write a numerical or variable expression for each quantity: the value in cents if 7nickels?

Answer 1

`7N=35` cents.

Explanation:

We're being asked to write an expression that expresses the value, in cents, of seven nickels.

First we need to know the value of a nickel. It's 5 cents. So let's write that as:

`N=5` cents, where N is a nickel.

Next step is to write down the number of nickels. There are 7 of them. Since `N` is one nickel, `7N` is seven nickels (we could also write it as `N+N+N+N+N+N+N`, but that gets tiring and confusing really quickly).

Ok, so if we have 7 nickels and so have `7N`, we have to multiply the other side, the `5`, by 7 as well, like this:

#7N=(7)(5) cents.

And we can simplify it to:

`7N=35` cents.

To write a variable expression for this (which would tell us how to calculate how many cents an unknown number of nickels would be), we would write it like this:

`xN=5x`, where x is the number of nickels.