Question

fatore a expressão abaixo
a² + ab - 72b²

Answer 1

Olá!

Note que:
$ab = 9ab - 8ab$

$a^2 + \textbf{ab} -72b^2 \\ \\ = a^2 + \textbf{9ab -8ab} -72b^2$
$\\ = \textbf{a} (a + 9b) \textbf{ -8b} (a + 9b) \\ \\ = \textbf{(a -8b)} (a + 9b) \\ \\ \boxed{\maths{ (a -8b)(a + 9b)} }$

Bons estudos!!

Answer 2

Resposta:

$\boxed{\mathsf{(a + 9b)(a - 8b)}}$

Explicação passo-a-passo:

$\\ \mathsf{a^2 + ab - 72b^2 =} \\\\ \mathsf{a^2 + (9ab - 8ab) - 72b^2 =} \\\\ \mathsf{(a^2 + 9ab) + (- 8ab - 72b^2) =} \\\\ \mathsf{a(a + 9b) - 8b(a + 9b) =} \\\\ \mathsf{(a + 9b) \cdot [a - 8b] =} \\\\ \boxed{\boxed{\mathsf{(a + 9b)(a - 8b)}}}$