1+2x/4-1/6x=-3-1/12*(6-x)

(12+6x-2x)/12=-3-1/2+x/12
(12+4x)/12=(x-42)/12
(12+4x)/12-(x-42)/12=0
(12+4x-x+42)/12=0
(54+3x)/12=0
(3*(18+x))/12=0
(18+x)/4=0
18+x=0
x=-18