Question

[Phạm Huy Hoàng]

\(3\frac{1}{417}\). \(\frac{1}{762}\)-\(\frac{1}{139}\).\(4\frac{761}{762}\)-\(\frac{4}{417.762}\)+\(\frac{5}{139}\)( tính nhanh)

Answer 1

[Nguyễn Bảo Trung]

M = (3+ 1/417).1/762 - 1/139(4 +761/762) - 4/417.762 + 5/139
= 3/762 + 1/417.762 - 4/139 - 761/139.762 - 4/417.762 + 5/139
= 3/762 - 3/417.762 + 1/139 - 761/139.762 =
= 1179/ 139.762 - 761/139.762 - 3/417.762 =
= 418/139.762 - 3/417.762 =418/139.762 - 1/139.762 = 417/139.762 = 3/762 = 1/254