Simplify -y^3 - 7 + 4 + 4y^3 + 11x^2 + 2x^2

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 surface area of the triangular prism is .

Which of the following circles have their centers in the third quadrant?