If sum of all the solutions of the equation 8 cos x ·( cos ((π)/6+x) · cos ((π)/6-x)-1/2)=1 in [0, π] is k π, then k is equal to:

If sum of all the solutions of the equation $\displaystyle 8 \cos x \cdot\left(\cos \left(\frac{\pi}{6}+x\right) \cdot \cos \left(\frac{\pi}{6}-x\right)-\frac{1}{2}\right)=1$ in $\displaystyle [0, \pi]$ is $\displaystyle \mathrm{k} \pi$, then k is equal to :