\(\left(7\cdot13+8\cdot13\right)\div\left(9\frac{2}{3}-y\right)=39\)
\(\Rightarrow\left[13\cdot\left(7+8\right)\right]\div\left(\frac{29}{3}-y\right)=39\)
\(\Rightarrow\left(13\cdot15\right)\div\left(\frac{29}{3}-y\right)=39\)
\(\Rightarrow195\div\left(\frac{29}{3}-y\right)=39\)
\(\Rightarrow\frac{29}{3}-y=\frac{195}{39}\)
\(\Rightarrow\frac{29}{3}-y=5\)
\(\Rightarrow y=\frac{29}{3}-5=\frac{4}{5}\)