Đáp án đúng: D
Giải chi tiết:\(\begin{array}{l}720:\left[ {41 - \left( {2x + 5} \right)} \right] = 40\\\,\,\,\,\,\,\,\,\,\,41 - \left( {2x + 5} \right)\,\,\,\,\,\,\, = 720:40\\\,\,\,\,\,\,\,\,\,\,41 - \left( {2x + 5} \right)\,\,\,\,\,\,\, = 18\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,2x + 5\,\,\,\,\,\,\,\,\,\, = 41 - 18\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,2x + 5\,\,\,\,\,\,\,\,\,\, = 23\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,2x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 23 - 5\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,2x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 18\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 18:2\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 9.\end{array}\)
Vậy \(x = 9.\)
Chọn D.