321,000,000 in scientific notation

Solve for x, y, and z. show all steps.

What is the value of x? enter your answer in the box. photo attached.

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.