The ratio has a total of 2+3=5 units, of which 2 correspond to the length of segment AM. The difference of x-coordinates Bx-Ax = 20-0 = 20. 2/5 of that amount is (2/5)*20 = 8, so the x-coordinate of M is
Mx = 8 + Ax = 8 + 0 = 8
The difference of y-coordinates is 0 - 15 = -15. 2/5 of that amount is (2/5)*(-15) = -6, so the y-coordinate of M is
... My = -6 + Ay = -6 + 15 = 9
The point M is (Mx, My) = (8, 9).