\[
\boxed{
 \left\{ {\frac {\rm d}{{\rm d}t}}x \left( t \right) =-3\,x \left( t \right) +48\,y \left( t \right) -28\,z \left( t \right) ,{\frac {\rm d}{{\rm d}t}}y \left( t \right) =-4\,x \left( t \right) +40\,y \left( t \right) -22\,z \left( t \right) ,{\frac {\rm d}{{\rm d}t}}z \left( t \right) =-6\,x \left( t \right) +57\,y \left( t \right) -31\,z \left( t \right)  \right\} }
\]