Question

(a+4)² - 3²
Factored out

Answer 1

`a = - 7`

`a = - 1`

Explanation:

`(a+4) {}^(2) - 3 {}^(2) \\ a {}^(2) + 8a + 16 - 9 \\ a {}^(2) + 8a + 7 \\ a {}^(2) + a + 7a + 7 \\ a(a + 1) + 7(a + 1) \\ (a + 7)(a + 1) \\ a + 7 = 0 \: \: \: \: or \: \: \: \: a + 1 = 0 \\ a = - 7 \: \: \: \: \: \: \: \: or \: \: \: a = - 1`