Question

Cuanto es (2x+1) (2x-1)

Answer 1

(2x + 1) . (2x - 1)          Usando (a-b) (a+b) = a^2 - b^2
(2x) - $1^2$
$2^{2}$ $x^{2}$ - $1^2$
$4x^{2}$ - $1^2$
$4x^{2}$- 1