SOLUTION: the difference between a number and it’s positive square root is 12 find the number.

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Question 1180669: the difference between a number and it’s positive square root is 12 find the number.
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

let a number be n
if the difference between a number and it’s positive square root is 12, we have
n-sqrt%28n%29=12
n-12=sqrt%28n%29....square both sides
%28n-12%29%5E2=%28sqrt%28n%29%29%5E2
n%5E2-24n%2B144=n
n%5E2-24n%2B144-n=0
n%5E2-25n%2B144=0
n%5E2-25n%2B144=0
%28n+-+16%29+%28n+-+9%29+=+0
solution:
%28n+-+16%29+=+0=>n=16
%28n+-+9%29+=+0=>n=9
check which solution works
n-sqrt%28n%29=12=>n=16
16-sqrt%2816%29=12
16-4=12
12=12-> this solution works
9-sqrt%289%29=12=>n=9
9-3=12
6%3C%3E12-> this solution does not work
so, the number is 16