Вправи: 369

369. Спростіть вираз:

1) (2р – 1)(3р + 5) – 6р² = 6р² + 10p – 3р – 5 – 6р² = 7p – 5;

2) 12 + (3m – 2)(5m + 6) = 12 + 15m² + 18m – 10m – 12 = 15m² +

+ 8m;

3) (m + 3)(m – 5) – m(m – 2) = m² – 5m + 3m – 15 – m² + 2m = –15;

4) (3а – 2)(4а + 1 ) – (12а² – 2) = 12а² + 3а – 8а – 2 – 12а² + 2 = –5а.