FX is an odd function defined on R, XF '(x) + F (x) on (- infinity, O)

FX is an odd function defined on R, XF '(x) + F (x) on (- infinity, O)

XF '(x) + F (x) = [XF (x)] & 39; & lt; 0, XF (x) on (- $, 0), XF (x) is decreasing, because the odd function is symmetric about the origin, so XF (x) also decreases at (0, + $), and f (- 2) = 0, & nbsp; so XF (- 2) = 0, we can draw a diagram of function y = XF (x) & nbsp; get the solution of XF (x) & lt; 0 at (- 2,0) U (2