2)
x^2 - 14x - 32 = x^2 - 16x + 2x - 32 = x(x-16) + 2(x-16) = (x - 16)(x + 2)
⇒ x^2 - 14x - 32 = (x - 16)(x + 2)
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3)
2n^2 - 7n - 15 =
= 2n^2 - 10n + 3n - 15 =
= 2n(n - 5) + 3(n - 5) =
= (n - 5)(2n + 3)
⇒ 2n^2 - 7n - 15 = (n - 5)(2n + 3)
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4)
x^2 - 25 = (x - 5)(x + 5)