Question Number 165355 by Ari last updated on 31/Jan/22
Answered by Ar Brandon last updated on 31/Jan/22
$$\begin{cases}{{x}+{y}−{z}=\mathrm{170}}\\{{z}+{y}−{x}=\mathrm{130}}\end{cases}\:\:\Rightarrow\mathrm{2}{y}=\mathrm{300}\Rightarrow{y}=\mathrm{150} \\ $$