Раскрыть скобки и привести подобные члены.
3m+(1+2m)
3m-(1+2m)
3m-(1-2m)
3m+(1+(2+m))
3m+(1+(2-m))
3m+(1-(2+m))
3m+(1-(2-m))
3m-(1-(2+m))
3m-(1-(2-m))