posted by mysterychicken .
Need help with these 2 please--
19. Nancy invests $100 in one account for 10 years at a 9% interest rate compounded annually, and she invests $150 in an account for 10 years at a 6% interest rate compounded semi-annually. How much money will she have in the accounts after 10 years?
20. Suppose Tyler sprayed around the house for ants. Which formula would be used to find the number of ants still alive after a certain time if the number of ants was changing exponentially?
a. a = P(o.56)^t
b. y = mx + b
c. a = x
d. a = P(1.23)^t