SOLUTION: The square of 9 more than a number is equal to 9 more than the square of the number. What is the number? i tried but couldn't find the answer :( thought was nine at first so

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: The square of 9 more than a number is equal to 9 more than the square of the number. What is the number? i tried but couldn't find the answer :( thought was nine at first so       Log On


   



Question 818379: The square of 9 more than a number is equal to 9 more than the square of the number. What is the number?
i tried but couldn't find the answer :(
thought was nine at first so i tried ( i'm home schooled and it tells you if your wrong or right on practice test )

Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
(n+9)^2=n^2+9
n^2+18n+81=n^2+9
18 n+72 = 0
n=-4
check
25=25
ok