Use node$-$voltage analysis to find the node voltages $($v$1$ and v$2),$ the voltage vx across the $10$ ohm resistor, the current through $15$ ohm, and the current through the two $5$ ohm resistors, in the circuit shown in Figure.You may use the substitution method, the free software Octave$,$ MATLAB or a scientific calculator to solve the linear system of equations to determinethe node voltages $($v$1$ and v$2).$Include ALL step$-$by$-$step calculations