Помогите со 2,3 номером

2) а) 9х² - 4 = (3х - 2)(3х + 2)

б) 49 - 25у² = (7 - 5у)(7 + 5у)

в) 4а² - 20аb + 25b² = (2a - 5b)² =

= (2a - 5b)(2a - 5b)

г) 8ab + b² + 16a² = (4a + b)² =

= (4a + b)(4a + b)

3) a) (x + 2)(x - 2) - x(x - 3) = 0

x² - 4 - x² + 3x = 0

3x = 4

x = 4/3 = 1⅓

б) x² - 1 = 0

(x -1)(x + 1) = 0

x - 1 = 0. x + 1 = 0.

x = 1. x = -1. или х = √1 = ±1