Hej!
a)
(2x - 5)(2x + 5) = (2x)² - 5² = 4x² - 25
b)
6(3d - 1)(2d + 1) = 6(6d² + 3d - 2d - 1) =
= 6(6d² + d - 1) = 36d² + 6d - 6
Pozdrawiam! - Julka
