If ∫ (d x)/((x^2+x+1)^2)= a tan^-1((2 x+1)/(√ 3))+ b ((2 x+1)/(x^2+x+1))+ C, x>0 where C is the constant of integration, then the value of 9(√ 3 a+b)…

If $\displaystyle \int \frac{\mathrm{d} x}{\left(x^2+x+1\right)^2}=\mathrm{a} \tan ^{-1}\left(\frac{2 x+1}{\sqrt{3}}\right)+\mathrm{b}\left(\frac{2 x+1}{x^2+x+1}\right)+\mathrm{C}, x>0$ where C is the constant of integration, then the value of $\displaystyle 9(\sqrt{3} a+b)$ is equal to \_\_\_\_.