Someone pls help me ill give out brainliest pls don’t answer if you don’t know

When y’all answer can y’all explain too !

A33 gram sample of a substance that's used to detect explosives has a k-value of 0.1473. n = noekt no = initial mass (at time t = 0) n = mass at time t k = a positive constant that depends on the substance itself and on the units used to measure time t = time, in days

Find the greatest common factor of the followig monomials 21u^5v,3u^4v^6, and 3u^2v^5