Question
Answer
$$(7-3i)\cdot(2+5i)=-15i^2+29i+14$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}(7-3i)\cdot(2+5i)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}14+35i-6i-15i^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}-15i^2+29i+14\end{aligned} $$ | |
| ① | Multiply each term of $ \left( \color{blue}{7-3i}\right) $ by each term in $ \left( 2+5i\right) $. $$ \left( \color{blue}{7-3i}\right) \cdot \left( 2+5i\right) = 14+35i-6i-15i^2 $$ |
| ② | Combine like terms: $$ 14+ \color{blue}{35i} \color{blue}{-6i} -15i^2 = -15i^2+ \color{blue}{29i} +14 $$ |
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