Example: Allez, aide-moi

Question

This example from the top of the page confuses me. Why is Allez conjugated in vous form and Aide is in tu form?

Ron Thomas · Answer

Bonjour Lily,
I think that may be a typo.
Tu m'aides avec mes devoirs?-Non.-Allez, aide-moi avec mes devoirs!
Are you helping me with my homework?-No.-Come on, help me with my homework!

Laura K Lawless · Answer

Bonjour Lily,

Allez isn't really a conjugated verb there, it's a filler that means "come on."

Allez, aide-moi ! Allez, on va partir.

Dori Hart · Answer

I have the same question... 'Allez," is in the vous form, but what follows is in the tu form "aide-moi"... Is it still grammatically correct to use "Allez" (as in Come on...) or is it better to say "Vas-y"...?