Which angle measures closest to 90°?

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

The population in a city is modeled by the equation p(d)= 100,000*(1+0.3) where d is the number of decades since 1970

Tiene pendiente -4 y pasa por el punto (-3,-2) encuentre la ecuación de la recta