\(\frac{11}{13}-\left(\frac{5}{42}-x\right)=-\left(\frac{15}{28}-\frac{11}{13}\right)\)
\(=\frac{11}{13}-\left(\frac{5}{42}-x\right)=\frac{113}{364}\)
\(\Rightarrow\frac{5}{42}-x=\frac{11}{13}-\frac{113}{364}\)
\(\Rightarrow x=\frac{5}{42}-\frac{15}{28}\)
\(\Rightarrow x=\frac{-5}{12}\)