Вправа 641 алгебра Бевз гдз 7 клас
№ 641
- a) (3a + 2p)2 – (a + p)2 = (3a + 2p – a – p)(3a + 2p + a + p) =
= (2a + p)(4a + 3p);
б) 9(p + q)2 – (p – q)2 = (3p + 3q – p + q)(3p + 3q + p – q) =
= (2p + 4q)(4p + 2q);
в) a4 – 2a2 + 1 – p2 + 2pc – с2 = (a2 – 1)2 – (p – c)2 =
= (a2 – 1 + p – c)(x2 – 1 – p + c);
г) p2 + 6pq + 9q2 – a2 + 4a – 4 = (p + 3q)2 – (a – 2)2 =
= (p + 3q + a – 2)(p + 3q – a + 2).
вправи поруч