Вправи: 620

620. Розклади на множники многочлен.

a) xa² – xc² = x(a² – c²) = x(a – c)(a + c);

б) a³ – an² = a(a² – n²) = a(a – n)(a + n);

в) 20x² – 5 = 5(4x² – 1) = 5(2x – 1)(2x + 1);

г) 100am² – 25ax² = 25a(4m² – x²) = 25a(2m – x)(2m + x);

ґ) 3x³ – 27x = 3x(x² – 9) = 3x(x – 3)(x + 3);

д) 45a – 5a³ = 5a(9 – a²) = 5a(3 – a)(3 + a).