Answer
$I=8+3i$
Work Step by Step
Plug in the given values to the formula $E=IZ$.
$57+67i=I(9+5i)$
Divide both sides by $(9+5i)$.
$\frac{57+67i}{9+5i}=I$
Multiply by top and bottom by the complex conjugate of the denominator.
$(\frac{9-5i}{9-5i})\frac{57+67i}{9+5i}=I$
Expand.
$\frac{513+603i-285i-335i^2}{81+45i-45i-25i^2}=I$
Combine like terms using the fact that $i^2=-1$.
$\frac{848+318i}{106}=8+3i=I$
$I=8+3i$
