Question

An airplane flies at a constant speed. It can travel a distance (d) of 1,800 kilometers in 2 hours (t).

Answer 1

D = 900t

because if you want to simplify t (2 hours) into one then you divide 1800 by 2 and that gives you the constant of proportionality (slope) of 900. Using this information you can write the expression d = 900t.