Help, I cant find the answer on this circle answer

If f(x)= 3x+6 which of the following is the inverse of f(x)

If np3 /nc2 = 6, find the value of n

Margaret is purchasing a house for $210,000 with a 15 year fixed rate mortgage at 4.75% interest she has made a 5% down payment the house is valued at 205,000 and the local tax rate is 3.5% homeowners insurance 600 per year what are her total monthly payment