Вправи 301 - 400 » 395

395. Запишіть як квадрат двочлена: 1) y–2 – 4y–1 + 4 = (y–1)2 – 2 • 2 • y–1 + 22 = (y–1 – 2)2; 2) x–2 – 2(xy)–1 + y–2 = (x–1)2 – 2 • x–1 • y–1 + (y–1)2 = (x–1 – y–1)2; 3) a–4 – 10a–2 + 25 = (a–2)2 – 2 • 5 • a–2 + 52 = (a–2 – 5)2; 4) 4m–2 – 12m–1n–1 + 9n–2 = (2m–1)2 – 2 • 6m–1 • n–1 + (3n–1)2 = (2m–1 – 3n–1)2; 5) a–2c–4 – 2a–1c–2 + 1 = (a–1c–2 – 1)2; 6) 9a–2b–2 – 6a–1b–2c–1 + c–2b–2 = b–2(9a–2 – 6a–1c–1 + c–2) = b–2(3a–1 – c–1)2.