Question
Answer
$$-4i\cdot5i=20$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}-4i\cdot5i& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-20i^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}20\end{aligned} $$ | |
| ① | $$ 4 i \cdot 5 i = 20 i^{1 + 1} = 20 i^2 $$ |
| ② | $$ -20i^2 = -20 \cdot (-1) = 20 $$ |
This page was created using
Complex Expression calculator