What are the resistance matrices $r1,r2,r3,r4,r5?$ Their sizes are $51.$

What is the resistance matrix $R,$ size $55,$ formed from $r1,r2,r3,r4,r5?$

What is the voltage matrix, size $51?$

Write the matrix equation $RI=V$

Use Wolfram Alpha to solve the matrix equation for the loop currents. If you have access to MatLab, Mathematica or other software you can use it$.$