Question

How do you translate "the difference of 7 and a number n" into a mathematical expression?

Answer 1

We can write it as `|n-7|`

Explanation:

Difference is different from subtraction.

While subracting a number, say `7` from `n`, the result is `n-7` and it could be positive or negative, depending on whether `7` is less than or more than `n`.

The difference, on the contrary is independent of sign and is always positive. For example, difference between `3` and `7` as well as `7` and `11` is `4`.

Hence to write the difference between `7` and `n`, we can write it as `|n-7|`, the absolute value of #n-7.