Lane of Lethargy states:
Lance of Lethargy Prerequisite: eldritch blast cantrip
Once on each of your turns when you hit a creature with your eldritch
blast, you can reduce that creature’s speed by 10 feet until the end
of your next turn.
Repelling blast states:
Repelling Blast Prerequisite: eldritch blast cantrip
When you hit a creature with eldritch blast, you can push the creature
up to 10 feet away from you in a straight line.
If a warlock hits a creature with a single beam can that character stack both affects of being pushed back 10′ and having their movement reduced by 10′?