How do you simplify (-a)(a+3)?

Aug 7, 2016

$\left(- a\right) \left(a + 3\right) = - {a}^{2} - 3 a$

Explanation:

The distributive property of multiplication states that for any $a , b , c$, we have

$a \left(b + c\right) = a b + a c$

Applying that here, we get

$\left(- a\right) \left(a + 3\right) = \left(- a\right) a + \left(- a\right) 3 = - {a}^{2} - 3 a$