how many free variables are in the system: a+b+c+d=1 a-b-c-d=2

how did you get I2= 45.45 angle -45.57 A? and where is the answer for current I1? Could you explain all of the steps of this solution and how you got each answer? I would really appreciate it.

Find the equations and Verify the loops and junctions rule if I1=0.06 I2=0.25 I3=0.4^ I4=0.74 I5=0.4 I6=0.32 R1=25 R2=45 R3=10 R4=15 R5=20 R6=40 e1= 10 , e2=35

We wish to carry out a subtraction using the circuit shown below.  We will subtract A - B where A = 3 and B = 6.   Assuming the everything is operating correctly with the circuit, determine the following values: The input to the 7483 chip at B2 is?  1 or 0                         The output Σ4Σ3Σ2Σ1Σ4Σ3Σ2Σ1 is?     0011, 0100, 1011, 1101, or 0110