Ответ:

  1. \(12x-5.14=59.66\)
    \(12x=59.66+5.14=64.8\)
    \(x=64.8:12=5.4\).
  2. \(34+(x-13.6)=74.8\)
    \(x-13.6=74.8-34=40.8\)
    \(x=40.8+13.6=54.4\).

Ответ: а) \(x=5,4\); б) \(x=54,4\).