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

1 Answer
Jun 13, 2016

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.