The first three terms of an arithmetic sequence are given. Find an expression for Tn in terms of n: a, 2a, 3a

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

Which type of graph would allow us to compare the median number of teeth for mammals and reptiles easily

60 2(x + 2) in the diagram, gef and hef are congruent. what is the value of x?