Given data:
The first equation is 3j +14=-5z.
The second equation is -10j=5z .
Add both the equations.
[tex]\begin{gathered} (3j+14)+(-10j)=-5z+5z \\ -7j+14=0 \\ 7j=14 \\ j=2 \end{gathered}[/tex]Substitute 2 for j in the first equation.
[tex]\begin{gathered} 3(2)+14=-5z \\ 20=-5z \\ z=-4 \end{gathered}[/tex]Thus, the value of j is 2 and z is -4.