## Intermediate Algebra (12th Edition)

$-10-30i$
$\bf{\text{Solution Outline:}}$ To simplify the given expression, $5i(-6+2i) ,$ use the Distributive Property. Then use $i^2=-1$. $\bf{\text{Solution Details:}}$ Using the Distributive Property which is given by $a(b+c)=ab+ac,$ the expression above is equivalent to \begin{array}{l}\require{cancel} 5i(-6)+5i(2i) \\\\= -30i+10i^2 .\end{array} Since $i^2=-1,$ the expression above is equivalent to \begin{array}{l}\require{cancel} -30i+10(-1) \\\\= -30i-10 \\\\= -10-30i .\end{array}