a. 13000mm+79hm-480dm=
=13000:1000m+79×100m-480:10m=
=13m+7900m-48m=
=7913m-48m=7865m
b. 31km+45hm-700m=
=31×1000m+45×100m-700m=
=31000m+4500m-700m=
=35500m-700m=34800m
