Question

(2x-5)(2x+5)-(x-3)(x+7)=0

Answer 1

(2x - 5)(2x + 5) - (x - 3)(x + 7) = 0
4x² - 25 - x² - 7x + 3x + 21 = 0
3x² - 4x- 4 = 0
D = (- 4)² - 4 * 3 * (- 4) = 16 + 48 = 64 = 8²

$x _{1} = \frac{4+8}{6}= 2\\x _{2}= \frac{4-8}{6}=- \frac{2}{3}$