Respuesta :

m=2, 1.2*2-3.6 = 2.4-3.6=-1.2 = -0.6*2, convinced?
1.2m − 3.6 = −0.6m
1.2m + 0.6m = 3.6
1.8m = 3.6
     m = 2

answer
m=2