Why is the sign of the number that is multiplied by the hours negative?

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

Anyone know these questions? i need ,.

|y + 2| > 6 {y|y < -8 or y > 4} {y|y < -6 or y > 6} {y|y < -4 or y > 4}