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Verified answer

1) 5a(a⁴ - 6a² + 3) = 5a⁵ - 30a³ + 15a
(x + 4)(3x - 2) = 3x² - 2x + 12x - 8 = 3x² + 10x - 8
(6m + 5n)(7m - 3n) = 42m² - 18mn + 35mn -15n² = 42m² + 17mn - 15n²
(x + 5)(x² + x - 6) = x³ + x² - 6x + 5x² + 5x - 30 = x³ + 6x² - x - 30
2) 18xy - 6x² = 6x(3y - x)
15a⁶ - 3a⁴ = 3a⁴(5a² - 1)
4x - 4y + cx - cy = (4x - 4y) + ( cx - cy) = 4(x - y) + c(x - y) = (x - y)(4 + c)
3) 3x² + 9x = 0
3x(x + 3) = 0
x(x + 3) = 0
или x = 0       или    x + 3 = 0
                                x = - 3
Ответ: - 3 ; 0
4) 7b(2b + 3) -(b + 6)(b - 5)= 7b² + 21b - b² + 5b - 6b + 30 = 6b² + 20b + 30