Write three ordered pairs for a direct variation relationship where y = 12 when x = 16

Element x decays radioactively with a half life of 8 minutes. if there are 450 grams of element x, how long, to the nearest tenth of a minute, would it take the element to decay to 37 grams?

Ihave trouble finding the nth term of a linear sequence

45 was divided by a power of ten to get 4.5. what power of ten was it divided by? people 4.5