Question

[ngô thị minh trang]

Rút gọn phân số sau : D=71 . 72 + 53 / 530 . 71 - 180

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Answer 1

[Ko cần bít]

\(D=\frac{71.72+53}{71.53.10-18.10}\)

\(D=\frac{71.72+53}{10.\left(71.53-18\right)}\)

\(D=\frac{71.72+53}{10.\left(71.52+72-18\right)}\)

\(D=\frac{71.72+53}{10.\left(71.52+53\right)}\)

Sau đó bạn tự tính tiếp :))

Answer 2

[Dương Đức Hiệp]

\(D=\frac{71\cdot72+53}{530.71-180}\)

\(D=\frac{71\cdot72+53}{53.10\cdot71-180}\)

\(D=\frac{72+53}{53\cdot10-180}\)

\(D=\frac{72+53\cdot1}{53\cdot10-180}\)

\(D=\frac{72}{53\cdot\left(10-1\right)-9\cdot20}\)

\(D=\frac{72}{53\cdot9-9\cdot20}\)

\(D=\frac{72}{\left(53-20\right)\cdot9}\)

\(D=\frac{72}{33\cdot9}\)

\(D=\frac{72}{297}=\frac{8}{33}\)