Answer
$E=(47+13i)$ volts
Work Step by Step
$I=(4-5i)$ amperes $;$ $R=(3+7i)$ ohms
Ohm's law is:
$$E=IR$$
where $I$ is the current in a circuit, $R$ is the resistance of the circuit and $E$ is the voltage of the circuit.
$I$ and $R$ are given and $E$ is to be found.
Substitute the known values into the formula:
$E=(4-5i)(3+7i)=...$
Evaluate the product:
$...=12+28i-15i-35i^{2}=...$
Substitute $i^{2}$ by $-1$ and simplify:
$...=12+28i-15i-35(-1)=...$
$...=12+28i-15i+35=...$
$...=47+13i$
The voltage in the circuit is $47+13i$ volts