Multiply. Write your answer in a + bi form.
-$( - 5 - 8 \mathrm { i } ) ^ { 2 }$
A) $- 10 - 16 i$
B) $- 39$
C) $25 + 64 i$
D) $- 39 + 80 \mathrm { i }$

Question

Quizplus · Accepted Answer

Using FOIL method, we get 
$$( - 5 - 8 \mathrm { i } ) ^ { 2 } = - 5 \cdot ( - 5) - 5 \cdot 8 \mathrm { i } - 8 \mathrm { i } \cdot ( - 5 ) - 8 \mathrm { i } \cdot 8 \mathrm { i } = 25 - 80 \mathrm { i } - 64 = - 39 - 80 \mathrm { i }$$
Therefore, the answer is D.

Multiply Write Your Answer in a + Bi Form (−5−8i)2( - 5 - 8 \mathrm { i } ) ^ { 2 }(−5−8i)2

Multiply Write Your Answer in a + Bi Form $( - 5 - 8 \mathrm { i } ) ^ { 2 }$