Point O is the centroid of

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

I'm confused on this could anyone me and show me what i need to do to solve it.

Which statements describe the solutions to the inequality x< -20 check all that apply. there are infinite solutions. each solution is negative. each solution is positive. the solutions are both positive and negative. the solutions contain only integer values. the solutions contain rational number values.