SOLUTION: Twice a number subtracted from the square of the number equals 15. what are the two possible numbers? Explain exactly how to work it out not just the solution.

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Twice a number subtracted from the square of the number equals 15. what are the two possible numbers? Explain exactly how to work it out not just the solution.      Log On


   

Question 878288: Twice a number subtracted from the square of the number equals 15. what are the two possible numbers? Explain exactly how to work it out not just the solution.
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
N%5E2-2N=15
N%5E2-2N-15=0
Factor,
%28N-5%29%28N%2B3%29=0
Two solutions:
N-5=0
N=5
and
N%2B3=0
N=-3