Question

Can anyone please explain how to solve this problem?

The sum of a number and its square is 72. Find the number.

Answer 1

Is this the correct formula to start : n + n^2 = 72

Answer 2

ya.....let the number be n
n+n^2=72
n^2+n-72=0
n^2+8n-9n-72=0
n(n+8)-9(n+8)=0
(n+8)(n-9)=0

Answer 3

n=9 and -8 value is rejected.....

Answer 4

Thank you!!!

Answer 5

I would tweak the answers. (n+8)(n-9) is not n^2 +n -72

And I don't see any reason to exclude a negative number as a possible answer.