Assign solution set to a matrix

Here is the set of equations that I get the solutions:
using HomotopyContinuation

@var a2 a3 b2 b3

s3=1 + a2^3 + a3^3

s2t= 3(a2^2)*b2 + 3(a3^2)*b3

st2= 3a2*(b2^2) + 3a3*(b3^2)

t3=1 + b2^3 + b3^3


result = solve(f)

The first question is that after getting the solution set, how do I put the solutions in the matrix of the form A=[1 0 a2 a3; 0 1 b2 b3] and do RREF.

The second question is the solutions in HomotopyContinuation are quite tricky that they don’t print zero instead a very small number. How do I round up the small number to zero?

Thank you!