Question

-23.79=-24e^(-0.25r)

Answer 1

anyone here to help me figure this out?

Answer 2

Welcome to Open Study :)
To solve for r first multiply both sides by -1 then take natural logs of both sides. Can you do that?

Answer 3

so that would be 23.79= 24e^(-0.25r)

Answer 4

So far so good. Now take ln of both sides. Can you do that?

Answer 5

ok so now i have ln(3.169)= ln24e^(-0.25r)

Answer 6

What you need is this:
ln 23.79 = ln 24 + ln e^(-0.25r) = ln 24 + (-0.25r)
Do you follow?

Answer 7

Note that ln e^(-0.25r) = -0.25r.
Also when multiplying 24 and e^(-0.25r) using logs, the logs of each quantity must be added.

Answer 8

ok, wat should i do next?

Answer 9

We have arrived at the following equation:
ln 23.79 = ln 24 - 0.25r
Rearranging gives the following:
0.25r = (ln 24) - (ln 23.79)
Can you now solve for r ?

Answer 10

thank u. got it

Answer 11

Good! Well done :)
Please let me know if you need more help.