3x-y=-1 -3x-y=5 subtraction elimination

Three times the sum of a number and seven is negative thirty-six. what is the number?

Need ! the total ticket sales for a high school basketball game were $2,260. the ticket price for students were $2.25 less than the adult ticket price. the number of adult tickets sold was 230, and the number of student tickets sold was 180. what was the price of an adult ticket?

Which expression is equivalent to -5(3x - 6/7)