SOLUTION: Hi I need a bit of help. Find a negative number whose square is 12 more than itself. X represents the number. I got -(x)+12=x^2 or x+12=x^2 Do I put the - and the brackets? F

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Question 1171384: Hi I need a bit of help.
Find a negative number whose square is 12 more than itself.
X represents the number.
I got -(x)+12=x^2 or x+12=x^2
Do I put the - and the brackets?
For the first equation with brackets I get x=-4 but for the second equation without brackets I get x=-3.
Thanks
Found 2 solutions by Boreal, MathTherapy:
Answer by Boreal(15235)   (Show Source): You can put this solution on YOUR website!
(-x)^2=-x+12
x^2-x-12=0
and x=4 and -3
only -3 is negative
and -3 squared is 9, 12 more than -3.
-
4^2 is 16, 12 more than 4. But 4 is not negative.
(-4)^2 is 16, 20 more than -4.
-
Answering your question, the - goes in the brackets. The whole negative number is being squared.
-
The answer is -3.
Answer by MathTherapy(10552)   (Show Source): You can put this solution on YOUR website!

Hi I need a bit of help.
Find a negative number whose square is 12 more than itself.
X represents the number.
I got -(x)+12=x^2 or x+12=x^2
Do I put the - and the brackets?
For the first equation with brackets I get x=-4 but for the second equation without brackets I get x=-3.
Thanks
Note that the other person who responded has the WRONG SETUP!

You DON'T place a "-" in front of the variable. So, with the number being N, the equation is: 

(N + 3)(N - 4) = 0

Number or            OR           N = 4 (ignore) 

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