[R] analytic solution for equation

[Stephane Dray]

Hello,
I have search on R website but do not find any solution.
I would like to know if R has some functionalities to produce analytical results
of equation. or more generally if it contains some functions to simplify equation.

For example:
I would like to obtain x1 from:
x1+x2=8  (x1=8-x2)

x1^2+x2=8 (x1=sqrt(8-x2))



Is is possible in R ? if not, do you know a (free) software that could do the job ?

Thanks in advance !

Stephane DRAY