Which expression is equal to (x+5)(−3x2+15x−1)?

Can someone answer this question? : )

For each proportion find the unknown number x 1/5/8=×/15

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.