Đáp án đúng: D
Giải chi tiết:*Cách 1:
\(\begin{array}{l}x:5 - 115:5 = 19\\x:5 - 23 = 19\\x:5\,\,\,\,\,\,\,\,\,\,\, = 19 + 23\\x:5\,\,\,\,\,\,\,\,\,\,\, = \,42\\x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 42 \times 5\\x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = \,210\end{array}\)
*Cách 2 :
\(\begin{array}{l}\left( {x - 115} \right):5 = 19\\x - 115\,\,\,\,\,\,\,\,\,\, = 19 \times 5\\x - 115\,\,\,\,\,\,\,\,\,\, = \,95\\x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 95 + 115\\x\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = \,210\end{array}\)
Vậy \(x = 210\).
Chọn D
