## Precalculus (6th Edition)

$E=260+20i$
$I=20+12i$ $;$ $Z=10-5i$ Ohm's Law is defined by the equation $E=IZ$. In this case, $E$ is unknown. Substitute $I$ and $Z$ into Ohm's Law equation: $E=(20+12i)(10-5i)=...$ Evaluate the product indicated to find $E$. Do so by multiplying each term of the first factor by every term of the second factor: $...=200-100i+120i-60i^{2}=...$ Substitute $i^{2}$ by $-1$ and simplify: $...=200+20i-60(-1)=200+20i+60=260+20i$