Question 821237: When three times a number is added to the square of a number, the result is 10. Find the number Answer by LinnW(1048) (Show Source):
You can put this solution on YOUR website! let n = the number
n^2 + 3n = 10
subtract 10 from each side.
n^2 + 3n - 10 = 0
(n + 5)(n - 2) = 0
Either n + 5 = 0 or n - 2 = 0
So n = -5 or n = 2
Substituting -5 in the original equation we have
(-5)^2 + 3(5) ?= 10
25 + 15 not = 10
so -5 is not a solution.
Substituting 2 in the original equation we have
(2)^2 + 3(2) ?= 10
4 + 6 = 10
So our solution is n = 2
