Question

John has $5000. He decides to put $1000 in his piggy bank. The remaining $4000 he invests in Microsoft stock. This stock he purchases decreases in value by 10% each month. Model an exponential function using a table.

Answer 1

to decrease a number by 10% multiply it by \(.9\)

Answer 2

to decrease a number by 10% repeatedly, multiply it by \((.9)^t\) where \(t\) is the number of times you decrease it

Answer 3

you can use
\[400(.9)^t\] where \(t\) is time in months
since you save $1000 your total after \(t\) months is
\[1000+4000(.9)^t\]

Answer 4

is that my total amount john has?

Answer 5

yes, after \(t\) months

Answer 6

Thank you!

Answer 7

after 10 months how would i find the total amount john has?

Answer 8

I understand now never mind~