# How do you simplify 4(5a - 3)?

Use the $\textcolor{b l u e}{\text{distributive law}}$ which means multiply each term inside the bracket by the 4 outside.
$\Rightarrow \textcolor{red}{4} \left(5 a - 3\right) = \left(\textcolor{red}{4} \times 5 a\right) + \left(\textcolor{red}{4} \times \left(- 3\right)\right) = 20 a - 12$
$\Rightarrow 4 \left(5 a - 3\right) = 20 a - 12$