Solve the given problems. Refer to Example 4.

In an alternating-current circuit, two impedances Z₁ and Z₂ have a total impedance Z_T of 

Find Z_T for Z₁ = 3.2  + 4.8j mΩ and Z₂ = 4.8 − 6.4j mΩ.

Data from Example 4

In an alternating-current circuit, the voltage E is given by E = IZ, where I is the current (in A) and Z is the impedance (inΩ). Each of these can be represented by complex numbers. Find the complex number representation for I if E = 4.20 − 3.00j volts and Z = 5.30 + 2.65j ohms.
Because I = E/Z , we have

ZT ZZ Z + Z