Algebra (word problems)
posted by Colin on .
1) a small pipe can fill a tank in 16 min more time than it takes a large pipe to fill the same tank. Working together, both pipes can fill the tank in 6 min. How long would it take each pipe working alone to fill the tank?
2) a car travels 240 mi. a second car, travelling 12 mph faster than the first, makes the same trip in 1h less time. Find the speed of each car
3)a software manufacturer has determined that 500 copies per week of a new computer program will be sold at a price of $100. at a price of $110, the number of copies sold per week would decrease to 450. Determine a linear function that will predict the number of copies that would be sold at a price of $150
4)The financial manager of a hotel has determined that 600 rooms per night will be rented if the room rate per night is $120. For each $10 increase in price of a room, 20 fewer rooms will be rented. Determine a linear function that will predict the number of rooms that will be rented for any given price per room. use this model to predict the number of rooms that will be rented if the room rate is $150
5)a gerneral building contractor estimates that the cost to build a new house is $50,000 plus $70 for each square foot of floor space in the house. determine a linear function that will give the cost of building a house that contains a given number of square feet. use this model to determine the cost of building a house that contains 6000 feet.
Thanks for any help!

Please post your questions one at a time and show your own effort. We will guide you through the thought process but will not do your homework for you.

dude i did my own effort. the problem is i don't know what im doing with these. i missed class cuz i was sick but if i can get the answers or if you would be so kind as to take the time to explain to me how to do a problem of 2 that would be great. id give u what i have but i know for a fact its so off base it wouldnt even matter

2) Let V be the speed of the slower car. The faster car's speed is V + 12
The times requred are 240/V and 240/(V+12) The first of these is 1 hour longer.
Therefore
240/(V+12) = 240/V  1
Solve that algebraic equation for V. Multiply each term by V(V+12) to get rid of the fractions.
240 V = 240 (V+12)  V(V+12)
240*12 = 2880 = V^2 + 12 V
That quadratic equation can be factored for two answers, dude. Take the positive root. 
thank u