\(\frac{-3\left(x+4\right)}{3\left(4-x\right)}=-\frac{2}{3}\)
\(\Rightarrow\frac{3\left(x+4\right)}{3\left(4-x\right)}=\frac{2}{3}\)
\(\Rightarrow3\left(x+4\right)3=3\left(4-x\right)2\)
\(\Rightarrow9\left(x+4\right)=6\left(4-x\right)\)
\(\Rightarrow9x+36=24-6x\)
\(\Rightarrow6x+9x=24-36\)
\(\Rightarrow15x=-12\Rightarrow x=\frac{-12}{15}=\frac{-4}{5}\)