Answer
$$(11-i)\cdot(2+i)=-i^2+9i+22$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}(11-i)\cdot(2+i)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}22+11i-2i-i^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}-i^2+9i+22\end{aligned} $$ | |
| ① | Multiply each term of $ \left( \color{blue}{11-i}\right) $ by each term in $ \left( 2+i\right) $. $$ \left( \color{blue}{11-i}\right) \cdot \left( 2+i\right) = 22+11i-2i-i^2 $$ |
| ② | Combine like terms: $$ 22+ \color{blue}{11i} \color{blue}{-2i} -i^2 = -i^2+ \color{blue}{9i} +22 $$ |
This page was created using
Complex Expression calculator