Bobby the plumber charges $90
for a house visit and $55 an hour
for any time he spends over
30 minutes. write an algebraic
expression that represents the cost
of a house visit for h hours. then
simplify your expression.

According to modern science, earth is about 4.5 billion years old and written human history extends back about 10,000 years. suppose the entire history of earth is represented with a 10-meter-long timeline, with the birth of earth on one end and today at the other end.

Sarah took the advertising department from her company on a round trip to meet with a potential client. including sarah a total of 11 people took the trip. she was able to purchase coach tickets for $280 and first class tickets for $1280. she used her total budget for airfare for the trip, which was $6080. how many first class tickets did she buy? how many coach tickets did she buy?

Jimmy can run 3.5 miles in 20 minutes. how far can ne run in one hour and ten minutes?