Help me pls i dont get it lol

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).

Find the measure for the angle indicated in bold

Aline passes through the points (5,4) and (2.1). part a.) what is the slope of the line that passes through these points? show work. part b.) what is the equation of the line that passes through these points. show work. part c.) where does the line intercept on the x& y axis? show work