Let #f(x)=(3x+6)/(2x-12)=(3(x+2))/(2(x-6))#
Let's build the sign chart
#color(white)(aaaa)##x##color(white)(aaaa)##-oo##color(white)(aaaaaa)##-2##color(white)(aaaaaaa)##6##color(white)(aaaaaa)##+oo#
#color(white)(aaaa)##x+2##color(white)(aaaaaa)##-##color(white)(aaa)##0##color(white)(aaa)##+##color(white)(aaaaaa)##+#
#color(white)(aaaa)##x-6##color(white)(aaaaaa)##-##color(white)(aaa)##0##color(white)(aaa)##-##color(white)(aa)##||##color(white)(aaa)##+#
#color(white)(aaaa)##f(x)##color(white)(aaaaaaa)##+##color(white)(aaa)##0##color(white)(aaa)##-##color(white)(aa)##||##color(white)(aaa)##+#
Therefore,
#f(x)<=0# when #x in [-2,6)#
graph{(3x+6)/(2x-12) [-22.8, 22.83, -11.4, 11.4]}