Номер 23.11

1) (a–1 – 2) (a–1 + 2);

2) (a–2b–3 – 1)(a–2b–3 + 1);

3) (5x–4y–6 – z–1)(5x–4y–6 + z–1);

4) (a–1 + b–1) (a–2 – a–1b–1 + b–2);

5) m–4 – 6m–2p–1 + 9p–2 = (m–2 – 3p–1)2;

6) (a–4 + 7a–1)(a–4 – 7a–1);