Answer :
[tex]Sum\ of\ congrugent\ angles\ is\ 180^{\circ}.\\\\
LNM+JNL=180^{\circ}\\\\
8x+12+12x-32=180\\\\
20x-20=180 \ \ \ |Add\ 20\\\\
20x=200\ \ \ |Divide\ by\ 20\\\\
x=10\\\\
JNL=12x-32=12*10-32=120-32=88^{\circ}[/tex]