Please help with this!! It’s vertical/adjacent/complementary angles (algebraic)

Samantha swam upstream for some distance in one hour. she then swam downstream the same river for the same distance in only 12 minutes. if the river flows at 4 mph, how fast can samantha swim in still water?

You decide instead to take the train there. the train will take 135 minutes. convert this into hours and minutes.

Which expression is equivalent to 8(k + m) − 15(2k + 5m)?