Вправи 201 - 342 » 278

278. Подайте у вигляді добутку вираз: 1) х–4 – 25 = (х–2)2 – 52 = (х–2 – 5)(х–2 + 5); 2) m–6 – 8n–3 = (m–2)3 – (2n–1)3 = (m–2 – 2n–1)(m–4 + 2m– 2n–1 + 4n–2); 3) a–10 + 8а–5b–7 + 16b–14 = (а–5)2 + 2а–5 • 4b–7 + (4b–7)2 = (а–5 + 4b–7)2; 4) а–4 – а–2 = а–4(1 – а2) = а–4(1 – а)(1 + а).