= (2b - 4)(b - 3) - (b - 1)(b + 3) = 2b² - 4b - 6b + 12 - (b² - b + 3b - 3) =
= 2b² - 10b + 12 - b² + b - 3b + 3 = (2b² - b²) + (b - 10b - 3b) + (12 + 3) =
= b² - 12b + 15.
при b = -8
(-8)² - 12 · (-8) + 15 = 64 + 96 + 15 = 175.
ответ: 175.
= (2b - 4)(b - 3) - (b - 1)(b + 3) = 2b² - 4b - 6b + 12 - (b² - b + 3b - 3) =
= 2b² - 10b + 12 - b² + b - 3b + 3 = (2b² - b²) + (b - 10b - 3b) + (12 + 3) =
= b² - 12b + 15.
при b = -8
(-8)² - 12 · (-8) + 15 = 64 + 96 + 15 = 175.
ответ: 175.