$$ \begin{aligned} &\text { The balanced reaction is, }\\ &\begin{aligned} & \mathrm{Cr}_2 \mathrm{O}_7^{2-}+14 \mathrm{H}^{+}+6 \mathrm{e}^{-} \rightarrow 2 \mathrm{Cr}^{3+}+7 \mathrm{H}_2 \mathrm{O} \\ & \mathrm{x}=14 \end{aligned} \end{aligned} $$ $$ \begin{aligned} & Y=6 \\ & A=7 \end{aligned} $$