Answer:GCF is the Greatest Common Factor. So what you have to do is find the greastest factor 12 and 21 has in common.
Step-by-step explanation: go to learnzillion.com
S-t-upid people everywhere
They make me want to pull your hair
Don’t get me wrong I think you’re cool
But all the others are just fools
We’re going places this ain’t fair
This cycle is getting me nowhere
At night I close my eyes and dream
Humans are more of an i-d-i-o-t than they seem
Emptiness surrounds this hole
Of what? Well I don’t really know
Don’t no but will check on goggles
