SOLUTION: please help me solve this problem: (x+8)(x-2)<0 Thank You

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Question 62826: please help me solve this problem: (x+8)(x-2)<0
Thank You
Answer by praseenakos@yahoo.com(507) About Me  (Show Source):
You can put this solution on YOUR website!
QUESTION:

(x+8)(x-2)<0
ANSWER:
(x+8)(x-2)<0
Remove the brackets by multiplying term by term,
x*x - x*2 + 8* x - 8*2 < 0
x^2- 2x + 8x -16 < 0
x^2 + 6x -16 < 0
We can solve this equation using quadratic formula,


x++%3C++%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+

Here a = 1 b = 6 and c = -16

x++%3C++%28-6+%2B-+sqrt%28+6%5E2-4%2A1%2A-16%29%29%2F%282%2A1%29+

x++%3C++%28-6+%2B-+sqrt%28+36%2B64+%29%29%2F%282%29+

x++%3C++%28-6+%2B-+sqrt%28+100%29%29%2F%282%29+

x++%3C++%28-6+%2B-+10%29%2F%282%29+
==> x < (-6 + 10)/2 or

x < ( -6 - 10 )/ 2


==> x < 4 /2 or

x < -16/2



==> x < 2 or

x < -8

This the required solutions.


Regards.
praseenakos@yahoo.co.in