\(cos2\left(x+\frac{\pi}{6}\right)+4cos\left(\frac{\pi}{3}-x\right)=\frac{5}{2}\)
\(4sin\left(x+\frac{\pi}{6}\right)+\left(x+\frac{\pi}{6}\right)cos2=\frac{5}{2}\)
\(\frac{1}{6}\left(24sin\right)\left(x+\frac{\pi}{6}\right)+6x\left(cos2\right)=\frac{5}{2}\)
\(2\sqrt{3}sin\left(x\right)+x\)\(cos\left(2\right)+2cos\left(x\right)+\frac{1}{6}\pi\)\(cos\left(2\right)=\frac{5}{2}\)
\(\left(2\sqrt[6]{-1}-2\left(-1^{\frac{5}{6}}\right)\right)sin\left(x\right)+x\left(cos2\right)+\left(2\sqrt[3]{-1-2\left(-1^{\frac{2}{3}}\right)}\right)cos\left(x\right)=\frac{5}{2}-\frac{1}{6}\pi\)\(cos\left(2\right)\)
\(24sin\left(x+\frac{\pi}{6}\right)+\left(6x+\pi\right)cos\left(2\right)=15\)
\(4sin\left(x+\frac{\pi}{6}\right)+x\)\(cos\left(2\right)+\frac{1}{6}\pi\)\(cos\left(2\right)=\frac{5}{2}\)
\(\Rightarrow x=\left\{-15,1252;-13,976;-6,8388;-3,93832\right\}\)