Mr. Chang and his wife together had an unpaid balance of $500 on their credit cards for one month. THe bank that issued Mr. Chang's credit card charges an intrest rate of 1.25% a month and his wife's interest is 1.5 per month. If the total interest finance charge was $6.75 how much was each unpaid balance? Write an equaiton for the finance chare and the balance.

1 answer

If Mr. C owes X, Mrs. C owes 500 - X.

The monthly interest paid is

0.0125X + 0.015*(500 - X) = 6.75

1.25X + 1.5(500 -X) = 675

75 = 0.25 X

Complete the solution for X. Then compute 500 - X