
Robert J. answered 11/13/12
Certified High School AP Calculus and Physics Teacher
Step 1. Factor 2x^3+9x^2-5x > 0
=> x(2x^2+9x-5) = x(2x-1)(x+5) > 0
Step 2. Find boundary points: x = -5, 0, 1/2
Step 3. Check intervals: (-oo, -5), (-5, 0), (0, 1/2) and (1/2, oo)
Step 4. Write answer: (-5, 0) U (1/2, oo)
Robert J.
You had a typo in "(2x2+9x+5)x > 0"11/13/12