Hi, Stanislav
I am not sure whether there is a function coping with this directly.
But, if you suspect how your expression should look like, for instance, in your case:
![q=a \text{K10}](/c/portal/getImageAttachment?filename=gif.png&userId=61922)
then you can use Solve[]
to find a
. FullSimplify[]
it (eventually with additional assumptions) and there is your result.