SOLUTION: If four times the square of a negative number is added to the product of 17 and the number the result is 15. Find the number.

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Question 307205: If four times the square of a negative number is added to the product of 17 and the number the result is 15. Find the number.
Answer by texttutoring(324) About Me  (Show Source):
You can put this solution on YOUR website!
Let's let x = the number.

4(x^2) + 17(-x) = 15
4x^2 -17x -15 =0

Factor (think what multiplies to -15 and adds up to -17 when you do FOIL?) to find:
(4x+3)(x-5)=0

So x=-3/4 or x=5

Because we know that our number is negative, the number is actually -5.