Multiply. Write the result in the form a + bi.
-$( 6 - 6 i ) ( 2 + 7 i )$
A) $- 42 i ^ { 2 } + 30 i + 12$
B) $54 + 30 \mathrm { i }$
C) $- 30 - 54 i$
D) $54 - 30 \mathrm { i }$

Question

Quizplus · Accepted Answer

To multiply the complex numbers $(6 - 6i)(2 + 7i)$, distribute each term in the first complex number across the terms in the second complex number: $6*2 + 6*7i - 6i*2 - 6i*7i$. This simplifies to $12 + 42i - 12i - 42i^2$. Since $i^2 = -1$, the expression becomes $12 + 30i + 42$, which simplifies to $54 + 30i$.

Multiply Write the Result in the Form a + Bi (6−6i)(2+7i)( 6 - 6 i ) ( 2 + 7 i )(6−6i)(2+7i)

Multiply Write the Result in the Form a + Bi $( 6 - 6 i ) ( 2 + 7 i )$