# Stuck for extracting M from log(M - A)

Logarithms problems.

### Stuck for extracting M from log(M - A)

Hi,

Here's a not too complex transformation but my skills stop here...

$$K = \frac{log(0.5)}{log\frac{M - S}{E - S}}$$

Now I transformed it because I want $$M$$, and $$K$$ is known:

$$=> \frac{log(0.5)}{K} = log\frac{M - S}{E - S}$$

$$=> \frac{log(0.5)}{K} = log(M - S) - log(E - S)$$

$$=> \frac{log(0.5)}{K} + log(E - S) = log(M - S)$$

So here I am stuck, I don't know how to extract $$M$$ from $$log(M - S)$$

Many thanks to all for your help
Greg
Guest

### Re: Stuck for extracting M from log(M - A)

Silly me...

$$=> M = 10^{((\frac{log(0.5)}{K} + log(E−S)) + S)}$$
Guest

### Re: Stuck for extracting M from log(M - A)

That's still a bit silly!

From $$log(M- S)= \frac{log(0.5)}{k}+ log(E- S)$$
$$log(M-S)= log(0.5^{1/k}(E- S)$$.
so $$M- S= 0.5^{1/k}(E- S)$$

$$M= S+ 0.5^{1/k}(E- S)$$.

HallsofIvy

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