How do i do this? leave detailed explanation.

10 ! a train starts from grand city and travels toward belleville 388 miles away. at the same time, a train starts from belleville and runs at the rate of 47 miles per hour toward grand city. they pass each other 4 hours later. find the rate of the train from grand city.

Abacteria population is tripling every hour. by what factor does the population change in 1/2 hour? select all that apply

Y=(x+3)(x-4)(x+1)^2 sulutions? multiplicity?