Originally Posted by

**nsganon101**
I have 3 equations:

k

_{1}e

^{k20} + k

_{3} = 0

k

_{1}e

^{k20.1} + k

_{3} = 1

k

_{1}e

^{k21} + k

_{3} = 100

I have simplified the first

equation to: k

_{1} = -k

_{3} and the second to:

k

_{1}e

^{k2} + k

_{3} = 100 and that's about the only real progress I've made. I was told the relation between k

_{1} and k

_{3} being inverse of each other is the key to it but everything I've tried hasn't given the right answer

As I read this, the original problem (which you really should have stated for us, to give us context) probably involved an equation something like [tex]A = k_1e^{k_2t} + k_3[/tex], and you were given pairs (t, A) of (0, 0), (0.1, 1), and (1, 100). For clarity, I might write your equations as [tex]k_1e^{0k_2} + k_3=0[/tex]

[tex]k_1e^{0.1k_2} + k_3=1[/tex]

[tex]k_1e^{k_2} + k_3=100[/tex]

You've seen that the first tells you that [tex]k_1 + k_3=0[/tex], so you can replace k_{3} with -k_{1} everywhere:[tex]k_1e^{0.1k_2} - k_1=1[/tex]

[tex]k_1e^{k_2} - k_1=100[/tex]

I might now solve one of these for k_{2} (in terms of k_{1}) and plug that into the other. Or it might be helpful to eliminate k_{1} by dividing one by the other!

Now, it isn't obvious that this can be solved exactly by algebra. It will be especially helpful at this point if you can tell us the exact wording of the original problem, rather than dropping us into the middle of your work with nothing to go by. You may have incorrect equations, or the instructions may call for something other than an algebraic solution, or give a hint as to a method to be used.

## Bookmarks