WHAT IS "The cube of twice a number" PLEASE HELP ASAP!

Two sides of a triangle mesure 20cm and 30cm. what is the measure of the third side

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 points are solutions to the linear inequality y < 0.5x + 2? check all that apply. (–3, –2) (–2, 1) (–1, –2) (–1, 2) (1, –2) (1, 2)