Anyone knows the answers of these questions

Which is an equation for the nth terms of the sequence 12,15,18,21

Klmn and pqrs are similar trapezoids. which side of pqrs corresponds to lm

Pamela has a 30-year, 5.75% mortgage on her $250,000 home. she has been paying on it for 5 years, and has recently hit some financial trouble. if her lender agreed to lower the interest rate on her $231,905.47 balance to 5.5%, what will her new payment be for the remainder of the loan?