For a nonlinear equation with several variable delays ẋ(t) = m ∑ k=1 fk(t, x(h1(t)), . . . , x(hl (t)))− g(t, x(t)), where the functions fk increase in some variables and decrease in the others, we obtain conditions when a positive solution exists on [0, ∞), as well as explore boundedness and persistence of solutions. Finally, we present sufficient… (More)