Answer
The given values of the variables are solutions of the system of equations.
$\text{See the steps below.}$
Work Step by Step
The system of equations is given by the following three equations:
$$\begin{cases}
3x+3y+2z=4\hspace{20pt} (1)\\[3mm]
x-y-z=0 \hspace{20pt} (2) \\[3mm]
2y-3z = -8 \hspace{20pt} (3)
\end{cases}$$
Plugging in $x=1 \text{, } y=-1 \text{ and } z=2$
$$\begin{cases}
3(1)+3(-1)+2(2) =3-3+4 = 4 \\[3mm]
1-(-1)-2= 2-2 = 0 \\[3mm]
2(-1)-3(2)= -2-6 = -8
\end{cases}$$
$\text{Since }x=1 \text{, } y=-1 \text{ and } z=2 \text{ satisfy the three equations, then}$
$x=1 \text{, } y=-1 \text{ and } z=2 \text{ are solutions of the system of equations.}$
