§ 3. МНОГОЧЛЕНИ » 316

а) (4x – 3)(3x + 4) + (2x – 3)(3x + 1); б) (2b – 7)(4b – 1) – (8b – 3)(b + 1); в) (x + 3y)(x2 – 3xy + 9y2) – 18y3; г) (a + b)(a + b – 1) – a(a – 1) – b(b – 1).