Xét tính đơn điệu hàm số y=1+4x-x^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?  

Solve this equation using substitution. {4x + y = −2} {4x + 6y = 44}

Tan198=asin164=? how to solve this? ?