Find the common difference of the arithmetic sequence -7, -1 ,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

Find the zeros of each function. f(x) = 6x^2 - 7x - 20

Which of the following domains provide a real value periods