[tex]\dfrac{x+6^0}{3}-\dfrac{2(-9^0+x)}{\sqrt{81}}=\dfrac{3^0}{\sqrt9}-\dfrac{x}{3^2}\\\\\dfrac{x+1}{3}-\dfrac{2(-1+x)}{9}=\dfrac{1}{3}-\dfrac{x}{9}\\\\\dfrac{x+1}{3}-\dfrac{-2+2x}{9}=\dfrac{1}{3}-\dfrac{x}{9}\Big|\cdot 9\\\\3(x+1)-(-2+2x)=3-x\\3x+3+2-2x=3-x\\2x=-2\\x=-1[/tex]
