How do you isolate the x in the equation y= 1x+2

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?  

Choose the linear inequality that describes the graph. the gray area represents the shaded region. a: y ≤ –4x – 2 b: y > –4x – 2 c: y ≥ –4x – 2 d: y < 4x – 2

Find the magnitude, correct to two decimal places, made by each of the following with positive direction of the x axis a) y= x the answer is 45° but i don’t know how