One app charges $3.90 to download and $.79 for each song bought. A second app is free to download and charges $1.09 for each song. How many songs would you have to buy for the apps to cost the same?

Number of songs =

Aschool puts on a play. the play costs $1,200 in expenses. the students charge $4.00 for tickets. there will be one performance of the play in an auditorium that seats 500 people. what is the domain of the function that shows the profit as a function of the number of tickets sold?  

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?

I'm confused on this could anyone me and show me what i need to do to solve it.