11.
8x(3x - 2) = 24x² - 16x
12.
(4a - 3)(a + 6) = 4a² + 24a - 3a - 18 = 4a² + 21a - 18
13.
[tex]5x^{2}-2y^{2} = (\sqrt{5}x + \sqrt{2}y)(\sqrt{5}x - \sqrt{2}y)[/tex]
14. (a + b) = a² + 2ab + b²
a) (x + 5)² = x² + 10x + 25
b) (2x + 3)² = 4x² + 12x + 9
15. (a - b)² = a² - 2b + b²
a) (x - 6)² = x² - 12x + 36
b) (3x - 5)² = 9x² - 30x + 24
16. (a + b)(a - b) = a² - b²
a) (x - 8)(x + 8) = x² - 8² = x² - 64
b) (6x + 2)(6x - 2) = (6x)² - 2² = 36x² - 4
