Can someone me with my homework i don't get it

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.

Which of the following quartic functions has x = –1 and x = –2 as its only two real zeroes?

If the value of cos330°is√3/2 then find cos 165°.