SOLUTION: Derrick is thinking of a negative integer. When he multiples the integer by itself and then adds three times the integer to the product, he gets 180. What is Derricks intger

Question 1029278: Derrick is thinking of a negative integer. When he multiples the integer by itself and then adds three times the integer to the product, he gets 180. What is Derricks intger
Answer by fractalier(6550) (Show Source): You can put this solution on YOUR website!
Let us call it x. Then we write
x*x + 3x = 180
Now let's solve it, remembering that we want the negative value for x...
x^2 + 3x - 180 = 0
Now factor it...
(x + 15)(x - 12) = 0
so that
x = -15 or x = 12
So we want the negative one, so
Derrick's integer is -15.
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