Вправи 401 - 467 » 408

408. Дано вираз: а4 + а3 + а–3 + а–4. Винесіть за дужки: 1) a4 + a3 + a–3 + a–4 = a(a4–1 + a3–1 + a–3–1 + a–4–1) = a(a3 + a2 + a–4 + a–5); 2) a4 + a3 + a–3 + a–4 = a3(a4–3 + 1 + a–3–3 + a–4–3) = a3(a + 1 + a–6 + a–7); 3) a4 + a3 + a–3 + a–4 = a–1(a4–(–1) + a3–(–1) + a–3–(–1) + a–4–(–1) = a–1(a5 + a4 + a–2 + a–3); 4) a4 + a3 + a–3 + a–4 = a–5(a4–(–5) + a3–(–5) + a–3–(–5) + a–4–(–5) = a–5(a9 + a8 + a2 + a).