B) Yes, (16,20) is on the line. This is because the equation of the line is y=5x/4. When you plug in 16 for x, you get 20.
C) no, (20,24) is not on the line. This is because when you plug in 20 for the equation, you get 25, which is not 24.
D) yes, (80,100) is on the line. When 80 is plugged in for x, you get 100.
E) y=5x/4