1)a^3+8=(a+2)(a^2-2a+4)
2)b^3-27=(b-3)(b^2+3b+9)
3)c^3-64=(c-4)(c^2+4c+16)
4)d^3+125=(d+5)(d^2-5d+25)
2) (4b - 1)(4b + 1) - (4b - 1)² = 16b² - 1 - (16b² - 8b + 1) = 16b² - 1 - 16b² + 8b - 1 = 8b - 2
При b = - 4: 8 * (- 4) - 2 = - 32 - 2 = - 34
3)
![\left \{ {{3x+2y=8} \atop {4x-y=7}} \right.](https://tex.z-dn.net/?f=%20%5Cleft%20%5C%7B%20%7B%7B3x%2B2y%3D8%7D%20%5Catop%20%7B4x-y%3D7%7D%7D%20%5Cright.%20)
![\left \{ {{3x+2y=8} \atop {y=4x-7}} \right.](https://tex.z-dn.net/?f=%20%5Cleft%20%5C%7B%20%7B%7B3x%2B2y%3D8%7D%20%5Catop%20%7By%3D4x-7%7D%7D%20%5Cright.%20)
3x + 2 (4x - 7) = 8
3x + 8x - 14 = 8
11x = 8 + 14
11x = 22
x = 2
![\left \{ {{x=2} \atop {y=4*2-7}} \right.](https://tex.z-dn.net/?f=%20%5Cleft%20%5C%7B%20%7B%7Bx%3D2%7D%20%5Catop%20%7By%3D4%2A2-7%7D%7D%20%5Cright.%20)
![\left \{ {{x=2} \atop {y=1}} \right.](https://tex.z-dn.net/?f=%20%5Cleft%20%5C%7B%20%7B%7Bx%3D2%7D%20%5Catop%20%7By%3D1%7D%7D%20%5Cright.%20)
Ответ: 1
4. А1, Б3, В2