Please help me ill give brainliest​

Which expression is equivalent to (9x - 3 1/ + 1 3/8)

The depth of a lake at a certain point, wich is a function of the distance of that point from shore, is 30 feet.

Expresa commuter train leaves downtown sation and travels at a average speed of 55 miles per hour towards the north side sation, which is 50miles away. thirty minutes later, express commuter train #7 leaves north side and travels at a average speed of 35miles per hour towards downtown sation. at the moment the two trains pass each other, how far(in miles) is train #12 from the downtown sation and how long(in minutes) has the #12 train been traveling