Answer
$a=5; x=\dfrac{3}{2}; y=0; z=9$
Work Step by Step
We have: $a=5$ and $x+2=3x-1$ and $-6y=5y$ and $z=9$
After solving each term equation, we get :
$x+2=3x-1\implies x+2-3x+1 =0 \\2x=3 \implies x=\dfrac{3}{2}$
Now, $-6y=5y \implies 5y+6y=0 \\ 11y=0 \\y=0$
Thus, we have: $a=5; x=\dfrac{3}{2}; y=0; z=9$
