Help please due soon

Write numerical coefficient of y² in the expression 2x² - 15xy – 7y²

Which of the following is not a subset of {1,2,3}?

Raymond just got done jumping at super bounce trampoline center. the total cost of his session was $43.25 . he had to pay a $7 entrance fee and $1.25 for every minute he was on the trampoline. write an equation to determine the number of minutes (t) that raymond was on the trampoline.