What do the smaller "1s" mean on the top of the first row of numbers in the standard algorithm

Two airplanes start at the same place and travel in opposite directions,one at 395 miles per hour and the other at 422 miles per hour. how many hours will it take for the planes to be 2451 miles apart?

In a tutoring session, 2/3 of an hour was spent reviewing math problems. adelina attended 3/4 of the tutoring session. how much time did adelina spend at the tutoring session?

1/4x+5=3/4. i can't get access to the answer to this question! and, my request on "contact us" will not go