(4b - 9)2 - (3b + 8)2 = (4b - 9 - (3b + 8))(4b - 9 + 3b + 8) = (4b - 9 - 3b - 8)(4b + 3b - 9 + 8) = (b - 17)(7b - 1).
(4b - 9)2 - (3b + 8)2 = (4b - 9 - (3b + 8))(4b - 9 + 3b + 8) = (4b - 9 - 3b - 8)(4b + 3b - 9 + 8) = (b - 17)(7b - 1).
ответ:(b - 17)(7b - 1).