Can you please answer this for me thank you​

Factor the expression using the gcf. the expression 21m−49n factored using the gcf

Three numbers x, y, and z are in the ratio 2: 7: 8. if 12 is subtracted from y, then three numbers form a geometric sequence (in the order x, y–12, z). find x, y, and z. there are 2 sets.

Ihonestly have no clue if it's each or none.