Ответ:\(12x-5.14=59.66\)\(12x=59.66+5.14=64.8\)\(x=64.8:12=5.4\).\(34+(x-13.6)=74.8\)\(x-13.6=74.8-34=40.8\)\(x=40.8+13.6=54.4\).Ответ: а) \(x=5,4\); б) \(x=54,4\).