The area of a circle with a diameter of 10 is pi units^2

One line passes through (-7,-4) and (5,4) . another line passes through the point (-4,6) and (6,-9)

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 of the following will form the composite function?