What is 2+2 I am very confused

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?  

The triangle shown has a hypotenuse with a length of 13 feet. the measure of angle a is 20 degrees. and the measure of angle b is 70 degrees. which of the following is closest to the length, in feet, of line segment ac? no need to use a calculator to find the trig numbers. each function is listed below. 4.4 5 12.2 35.7

Yvaries directly as x. y =90 when x=6. find y when x=13