Exercise 6 A couple buys a home and signs a mortgage contract for $120000 to be paid with monthly payments over a 25 -year period at j2=10.5%. After 5 years, they renegotiate the interest rate and refinance the loan at j2=7%. Determine: a) the monthly payment for the initial 5 -year period; b) the new monthly payment after 5 years; 3 points 3 points