# How do you simplify  -3(a+5)+9?

$- 3 a - 6$
$- 3 \left(a + 5\right) + 9$
$\left(- 3 a - 15\right) + 9$ $\textcolor{b l u e}{\text{ Distributive property: } - 3 \cdot a \mathmr{and} - 3 \cdot 5}$
$- 3 a - 15 + 9$ $\textcolor{b l u e}{\text{ Remove parentheses to make it more readable}}$
$- 3 a - 6$ $\textcolor{b l u e}{\text{ Add like terms: } - 15 + 9 = 6}$