Need help solving a simultaneous equation problem?

Question

I need to extract an expression for one of the constants 'k' or 'c' in terms of 'X1', 'Y1', 'X2', and 'Y2', then the other constant should follow easily.

Equations are:

Y1 = k * ln(X1 + c) and Y2 = k * ln (X2 + c)

I got as far as this then got stuck:

e^(Y1/k) - e^(Y2/k) = X1 - X2

Can anyone help......please.

Answer 1

its easy.
just cancel out the two Ks on both sides.
then bring down the ln.using ln division rule divide it. u will get a one on the other side. when u open up the ln, u get da ans!!
=)

Answer 2

the next step may be (e^Y1)^(1/k) - (e^Y2)^(1/k) = X1 - X2

By dividing the eqs you get Y1/Y2 = ln(X2+c) / ln(X1+c) which will reduce to (X1+c)^(Y1/Y2) = X2+c.

Unfortunately, after that I'm stuck.