2. Упростите выражение: а) 4m – 6m – 3m + 7 + m; б) –8(k – 3) + 4(k – 2) – 2(3k + 1); в) 5/9(3,6a – 3/5b) – 3,5(4/7a – 0,2b).

а) (4 – 6 – 3 + 1)m + 7 = –4m + 7.

б) –8k + 24 + 4k – 8 – 6k – 2 = (–8 + 4 – 6)k + (24 – 8 – 2) = –10k + 14.

в) 2a – 3/5b – 2a + 0,7b = (2 – 2)a + (–0,6 + 0,7)b = 0,1b.