How do I use fsolve to optimize SLAM given information matrix and information vector?

I know fsolve function in matlab is used for nonlinear function optimization and the syntax is given as:

x=fsolve(fun,xo,option)

Please, how would I apply this function to optimize a pose SLAM given the information matrix H and the information vector b. Where H = n by n matrix and b=n by 1 vector?

Thanks

[Walter Roberson]

https://openslam-org.github.io/bailey-slam.html