Five days after a tomato plant was planted, it measured 12.5 inches tall. seven days after it was planted, it measured 15 inches tall. if the rate of growth remained constant, what is the most reasonable starting height of the plant?

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