
Arturo O. answered 07/06/16
Tutor
5.0
(66)
Experienced Physics Teacher for Physics Tutoring
9x^3 + 6x^2 + x = 0
Factor it as much as you can:
9x^3 + 6x^2 + x = x(9x^2 + 6x + 1)
x=0 is one solution; use the quadratic formula to find two more:
x = {-6 ± √[(6)^2 - 4(9)(1)]} / (2*9) = (1/18)(-6 ± 0) = -1/3
So the solutions are x=0 with a multiplicity of 1, and x = -1/3 with a multiplicity of 2