25) 6x + 6x³ – 6 = 6 · ...

25) $$6x + 6x^3 – 6 = 6 \cdot \textbf{(x+x³-1)}$$

$$6 \cdot (x+x^3-1) = 6x + 6x^3 - 6$$

Ответ: (x+x³-1)