Question

Упростите выражение:
1) (2b-3)(4b+9)
2) (2c-6)(8c+5)-(5c+2)(5c-2)
3) 16m² - (3-4m) (3+4m)
4) (2x-1)² + (2x+1)²
5) (x-4)(x+4) - (x-8)²​

Answer 1

Ответ:

1) (2b - 3)(4b + 9) = 8b² + 18b - 12b - 27 = 8b² + 6b - 27

2) (2c - 6)(8c + 5) - (5c + 2)(5c - 2) = 16c² + 10c - 48c - 30 - (25c² - 4) = 16c² - 38c - 30 - 25c² + 4 = -9c² - 38c - 26

3) 16m² - (3 - 4m)(3 + 4m) = 16m² - (9 - 16m²) = 16m² - 9 + 16m² = 32m² - 9

4) (2x - 1)² + (2x + 1)² = 4x² - 4x + 1 + 4x² + 4x + 1 = 8x² + 2

5) (x - 4)(x + 4) - (x - 8)² = x² - 16 - (x² - 16x + 64) = x² - 16 - x² + 16x - 64 = 16x - 80