SOLUTION: Solve: {{{x^2-2x-15<0}}}

Algebra ->  Complex Numbers Imaginary Numbers Solvers and Lesson -> SOLUTION: Solve: {{{x^2-2x-15<0}}}      Log On


   

Question 882939: Solve: x%5E2-2x-15%3C0
Found 2 solutions by LinnW, MathTherapy:
Answer by LinnW(1048) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E2-2x-15%3C0
first solve
x%5E2-2x-15=0
%28x-5%29%2A%28x%2B2%29=0
x = 5 or x = -2
So for values of x between -2 and 5,
x^2-2x-15 is less than zero
(-2,5) is our solution

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!
Solve: x%5E2-2x-15%3C0


x%5E2+-+2x+-+15+%3C+0

x%5E2+-+2x+-+15+=+0 ---- Changing inequality to equality to determine CRITICAL POINTS.

(x + 3)(x - 5) = 0

Critical points: x+=+-+3_AND_x+=+5

Test intervals:  x < - 3, -+3+%3C+x+%3C+5, and x > 5

ONLY highlight_green%28highlight_green%28-+3+%3C+x+%3C+5%29%29 proves TRUE.