Ответ:

  1. \[6m-2.6=2m+\frac1{15}\Rightarrow4m=2.6+\frac1{15}=\frac{40}{15}=\frac83\Rightarrow m=\frac23.\]
  2. \[2c+0.2c-0.8c+3.4c=6\Rightarrow4.8c=6\Rightarrow c=1.25.\]

Ответ: а) \(m=\frac23\); б) \(c=1,25\).