Đáp án đúng: C
Giải chi tiết:\(\begin{array}{l}\,\,\,{\left( {x - 5} \right)^{2016}} = {\left( {x - 5} \right)^{2018}}\,\,\,\,\,\left( {x \ge 5} \right)\\\,\,\,\,\,\,\,\,\,{\left( {x - 5} \right)^{2016}} - {\left( {x - 5} \right)^{2018}} = 0\\\,\,\,\,\,\,\,\,\,\,{\left( {x - 5} \right)^{2016}} - {\left( {x - 5} \right)^{2016}}.{\left( {x - 5} \right)^2} = 0\\\,\,\,\,\,\,\,\,\,\,{\left( {x - 5} \right)^{2016}}\left[ {1 - {{\left( {x - 5} \right)}^2}} \right] = 0\\TH1:\,\,\,\,{\left( {x - 5} \right)^{2016}} = 0\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x - 5\,\,\,\,\,\,\,\,\,\,\,\, = 0\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 5.\\TH2:\,\,\,1 - {\left( {x - 5} \right)^2} = 0\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{\left( {x - 5} \right)^2}\,\,\,\, = 1\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x - 5\,\,\,\,\,\,\,\,\, = 1\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 1 + 5\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 6.\end{array}\)
Vậy \(x = 5\) hoặc \(x = 6.\)
Chọn C.
