Back (someone or something) up to (something) phrase
To be beside or share a border with something.
I suggest we adjourn to the bar which backs up to our company after work.
I often go fishing in the stream backing up to the rear of my house.
To move, maneuver or guide A (someone/something) towards B (someone/something else) that is behind A.
I'm new to driving, so can you assist me in backing the car up to the garage?
If he hadn't helped back me up to the gas station, I couldn't have had my car filled now.
The verb "back" must be conjugated according to its tense.
The origin of this phrase is not clear.
Used to express one's feelings when facing a bad situation
Man, my life really sucks. Life's a bitch and then you die.