How do you simplify (8-4i)(6+3i)?

Sep 14, 2016

60

Explanation:

distribute the brackets using, for example, the FOIL method.

$\Rightarrow \left(8 - 4 i\right) \left(6 + 3 i\right) = 48 + 24 i - 24 i - 12 {i}^{2} = 48 - 12 {i}^{2}$

$\textcolor{\mathmr{and} a n \ge}{\text{Reminder }} \textcolor{red}{\overline{\underline{| \textcolor{w h i t e}{\frac{a}{a}} \textcolor{b l a c k}{{i}^{2} = {\left(\sqrt{- 1}\right)}^{2} = - 1} \textcolor{w h i t e}{\frac{a}{a}} |}}}$

$\Rightarrow 48 - 12 {i}^{2} = 48 + 12 = 60$

Thus $\left(8 - 4 i\right) \left(6 + 3 i\right) = 60$