Write the following series in sigma notation. 8+18+28+38

What is not true about kl and mn? what is mn? (show your work)

Describe the domain and range of y=2(3)^x-2+5

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