Someone help asap!!! Will give brainlist :)

Answer:
[tex]a) \: constant \: of \: proportionality \: (k) \\ = \frac{90}{2} \\ = 45 \\ \\ b) \: \frac{distance}{time} = k \\ \therefore \: \frac{d}{t} = k \\ \\ c) \: \frac{d}{t} = k \\ \\ \therefore \: d = tk[/tex]