# solve exponential

I've just started to experiment with Sage, so I might be missing something simple here. What I'm trying to do is to solve the following equation:

```
var('t','k1','k2','y1','y2')
assume(k1>0,k2>0,y1>0,y2>0)
assume(k1,'real')
assume(k2,'real')
assume(y1,'real')
assume(y2,'real')
assume(t,'real')
solve(y1*exp(-t/k1)/k1 - y2*exp(-t/k2)/k2==0,t)
```

The result is`[e^(t/k2) == k1*y2*e^(t/k1)/(k2*y1)]`

, and not fully solved for some reason. I was expecting something like

```
t==ln(y2*k1/y1*k2)/(1/k2-1/k1)
```

http://trac.sagemath.org/ticket/20068

Thanks for reporting ! I added a confirmed_bug tag to track such issues.

Ah! I didn't know about this tag. Good.