using ublas to solve linear systems?

I'm trying to see if I can use ublas to solve a linear system of equations. Digging through the documentation, I find a description of a function called 'solve" that says "Solves a linear equation for a triangular matrix." There is also a formula, B = solve(A, B, tag) <------> B <- A-1 B But I just don't know what any of this means (even though I am a mathematician and quite fluent in linear algebra). So a) can ublas be used (without me implementing any additional algorithms) to solve a linear system of equations? b) what exactly does the function solve do?