Question

(2x + 5)^2-(2x-5)^2​

Answer 1

(2x)^2 - (5)^2

=4x^2-25

Answer 2

$\tt( {2x + 5)}^{2} - ( {2x - 5)}^{2}$

[using identity] - $\tt\blue {{a}^{2} - {b}^{2} = (a + b)(a - b)}$

$\tt( {2x + 5)}^{2} - ( {2x - 5)}^{2} \\ \\ \tt = [(2x + 5) + (2x - 5)] [(2x + 5) - (2x - 5)] \\ \\ \tt = (4x)(10) \\ \\ \tt = 40x$