Roger’s brother gave Roger his collection of coins when he left for college. At that time, the value of the collection was $720. Twelve years later, the collection was worth $1080. What is the rate of change? Don't forget your units. Using the problem from #6, explain the real-world meaning of the slope and y-intercept.

Abike shop sells you a bicycle for $63 and a helmet for $21. the total cost is 150% of what the shop spent originally. how much did the shop spend originally? how much profit did the bike shop earn by selling the bicycle and helmet to you ?

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 .