jmc

We can build a sign chart, but since all of the factors are linear, we can track what happens to the expression as $x$ increases. At $x=0,$ the expression is positive. As $x$ increases past 1, the expression becomes negative. As $x$ increases past 2, the expression becomes positive, and so on. Thus, the solution is $$x\in \boxed{(-\infty ,1)\cup (2,3)\cup (4,5)\cup (6,\infty )}.$$