Expert: Scott A Wilson - 9/30/2010

Question
The sum of three times a number and 7 more than the number is
the same as the difference between -11 and twice the number.
What is the number?

Answer
This menas 3n + n+7 = -11-2n or 3n + n+7 = 2n+11.

For the 1st case, the answer is found in 4n + 2n = -11-7,
so 6n = -18.  This gives n = -3, and that makes -11-2n negative, and it shouldn't be.

For the 2nd case, the answer is found in 4n - 2n = 11 - 7,
so 2n = 4, and that says n = 2.  Since the difference was 2n+11,
that is 4+11=15, which is a positive difference.  Note that differences are supppose to be positive.