Express 3a^2b^-1 with positive exponents

What is the quadric regression equation that fits these data

Me asap! what is the slope of this line? enter your answer in the box.

Problem 3 a bank charges a service fee of $7.50 per month for a checking account. a bank account has $85.00. if no money is deposited or withdrawn except the service charge, how many months until the account balance is negative