\(D=\frac{71.72+53}{71.53.10-18.10}\)
\(D=\frac{71.72+53}{10.\left(71.53-18\right)}\)
\(D=\frac{71.72+53}{10.\left(71.52+72-18\right)}\)
\(D=\frac{71.72+53}{10.\left(71.52+53\right)}\)
Sau đó bạn tự tính tiếp :))
\(D=\frac{71\cdot72+53}{530.71-180}\)
\(D=\frac{71\cdot72+53}{53.10\cdot71-180}\)
\(D=\frac{72+53}{53\cdot10-180}\)
\(D=\frac{72+53\cdot1}{53\cdot10-180}\)
\(D=\frac{72}{53\cdot\left(10-1\right)-9\cdot20}\)
\(D=\frac{72}{53\cdot9-9\cdot20}\)
\(D=\frac{72}{\left(53-20\right)\cdot9}\)
\(D=\frac{72}{33\cdot9}\)
\(D=\frac{72}{297}=\frac{8}{33}\)