Thank you
if this helps

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).

If you bought a stock last year for a price of $124, and it has gone down 5.6% since then, how much is the stock worth now, to the nearest tenth?

Answer for 15 points (look at the image)