For the circuit shown in Figure P28.32, we wish

to find the currents I1, I2, and I3.Use Kirchhoff’s rules

to obtain equations for (a) the upper loop, (b) the lower

loop, and (c) the junction on the left side. In each case,

suppress units for clarity and simplify, combining the

terms. (d) Solve the junction equation for I3. (e) Using the

equation found in part (d), eliminate I3 from the equation

found in part (b). (f) Solve the equations found in parts

(a) and (e) simultaneously for the two unknowns I1 and I2.

(g) Substitute the answers found in part (f) into the junction

equation found in part (d), solving for I3. (h) What is

the significance of the negative answer for I2?