Algebra 2HardSystems of Equations

Systems of Equations · Hard problem

Solve the system for $x$ , $y$ and $z$ .

\begin{cases} 3 x + 2 y - 4 z = 25 \\ 2 x + 2 y + z = -5 \\ - 4 x + 5 y - 5 z = -20 \end{cases}