SOLUTION: three times the square of a certain positive number exceeds six times the number by nine. Find the number.

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Question 199865: three times the square of a certain positive number exceeds six times the number by nine. Find the number.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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three times the square of a certain positive number exceeds six times the number by nine.
Find the number.
:
3x^2 = 6x + 9
Simplify, divide by 3
x^2 = 2x + 3
:
x^2 - 2x - 3 = 0
Factor
(x-3)(x+1) = 0
positive solution
x = 3
;
;
Check solution in original equation; 3x^2 = 6x + 9
3(3^2) = 6(3) + 9
3(9) = 18 + 9