SOLUTION: if the square of a number is decreased by 15, the result is equal to the number increased by 15. what is the number?

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Question 372543: if the square of a number is decreased by 15, the result is equal to the number increased by 15. what is the number?
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Let n = the number.
n%5E2-15+=+n%2B15 "...the square of a number (n) is decreased by 15, the result is equal to the number increased by 15."
Add 15 to both sides.
n%5E2+=+n%2B30 Subtract n from both sides.
n%5E2-n+=+30 Subtract 30 from both sides.
n%5E2-n-30+=+0 Solve this quadratic equation by factoring.
%28n%2B5%29%28n-6%29+=+0
n+=+-5 or n+=+6
As you can see, there are two answers:
-5 and 6