Question

Halla el resultado de (7a - 5b)² - (5a - 4b)².​

Answer 1

Respuesta:

$\left(7a-5b\right)^2-\left(5a-4b\right)^2$
= $49a^2-70ab+25b^2-\left(5a-4b\right)^2$
= $49a^2-70ab+25b^2-25a^2+40ab-16b^2$
= $49a^2-25a^2-70ab+40ab+25b^2-16b^2$
= $24a^2-70ab+40ab+25b^2-16b^2$
= $24a^2-30ab+25b^2-16b^2$
= $24a^2-30ab+9b^2$
= $3\left(8a^2-10ab+3b^2\right)$
= $3\left(2a-b\right)\left(4a-3b\right)$

Espero te ayude ∧∧