y = 15x + 10, where y is the total cost of renting a bicycle on the boardwalk for x hours. Determine whether the function is proportional or non-proportional. Explain.

Aline on the wall and a line on the floor are skew. always, sometimes, or never?

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

21 a stick 7 inches long is broken into two pieces, so that one piece is twice as long as the other one. how long are the two pieces?