12 roses cost 18.96 how much is 5 roses

X+ y = 5 ; x - y =3 solve using linear combination

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.

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)