Đáp án đúng: C
Giải chi tiết:\(\begin{array}{l}\,\left( {x - 1} \right) \times 5 = 290\\\,\,\,\,\,\,x - 1\,\,\,\,\,\,\,\,\,\,\, = 290:5\\\,\,\,\,\,\,x - 1\,\,\,\,\,\,\,\,\,\,\, = 58\\\,\,\,\,\,\,x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 58 + 1\\\,\,\,\,\,\,x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 59\end{array}\)
Vậy \(x = 59\)
Chọn C