I'm a fan of slabweld from bestmaterials from repairing several long basement slab cracks and a garage crack. It uses sand as a base and the slabweld locks it together. A couple years later, the crack exposed outside of the garage door has started to show signs of degradation, so may not be best for outdoor repairs exposed to moisture. No new basement slab cracks have appeared, and the internal repairs still look great after a couple of years.
I recommend an extra pair of hands since it sets pretty quick. I chased the cracks with a chisel first to remove any loose concrete, then vacuumed up the dust and material. Have one person for filling cracks with sand, the other to apply the slabweld (wear gloves, it does not come off easy). Try to do it all in one session. Wait for it to cure and angle grinder the excess material off.