Question
Answer
$$-4i\cdot(2+i)+6\cdot4i=16i+4$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}-4i\cdot(2+i)+6\cdot4i& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-4i\cdot(2+i)+24i \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}-(8i+4i^2)+24i \xlongequal{ } \\[1 em] & \xlongequal{ }-(8i-4)+24i \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}-8i+4+24i \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle4}{\textcircled {4}} } }}}16i+4\end{aligned} $$ | |
| ① | $$ 6 \cdot 4 i = 24 i $$ |
| ② | Multiply $ \color{blue}{4i} $ by $ \left( 2+i\right) $ $$ \color{blue}{4i} \cdot \left( 2+i\right) = 8i+4i^2 $$ |
| ③ | Remove the parentheses by changing the sign of each term within them. $$ - \left(8i-4 \right) = -8i+4 $$ |
| ④ | Combine like terms: $$ \color{blue}{-8i} +4+ \color{blue}{24i} = \color{blue}{16i} +4 $$ |
This page was created using
Complex Expression calculator