8.13. Solve the initial value problem $$ \left\{\begin{aligned} y_{1}^{\prime} &=-y_{1} & 8+2 y_{3}, & & y_{1}(0) 8=8-2 y_{3}^{\prime} &=& 2 y_{1} &+y_{2} &-2 y_{3}, & & y_{2} (0) &=& 0W y_{3}^{\prime} &=&-2 y_{1} & &+3 y_{3}, & & y_{3}(0) &=&-1 . \end{aligned} ight. $$ CS.JG.137