Simplify the following expression: 9 – 3x + (-6x) + 4

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?  

If a || b and e || f , what if the value of y ?

Use the elimination method to solve the systems of equations. choose the correct ordered pair. 7x+4y=39