Calculate the monthly payment need to pay off a $200,000 loan at 4% yearly interest over 20 year period. Recall that r is the monthly rate.

In a two-digit number the units' digit is 7 more than the tens' digit. the number with digits reversed is three times as large as the sum of the original number and the two digits. find the number.

Either enter an exact answer in terms of \piπ or use 3.143.14 for \piπ and enter your answer as a decimal.

Find the dimensions of the circle. area = 64π in.² r= in.