Algebra
posted by mysterychicken on .
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 semiannually. 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
Thanks
MC

19
first investment = 100(1.09)^10 = ....
2nd investment = 150(1.03)^20 = ....
20.
I see 2 equations which look exponential
Of these two one has a base < 1, so things decrease
and the other has a base > 1, causing things to increase.
mmmmhhhh?