\(D=\left(3+\frac{1}{417}\right).\frac{1}{762}-\frac{1}{139}\left(4+\frac{761}{762}\right)-\frac{4}{417.762}+\frac{5}{139}\)

=\(\frac{3}{762}+\frac{1}{417.762}-\frac{4}{139}-\frac{761}{139.762}-\frac{4}{417.762}+\frac{5}{139}\)

=\(\frac{3}{762}-\frac{1}{139.762}+\frac{1}{139}-\frac{761}{139.762}=\frac{3}{762}+\frac{1}{139}\left(-\frac{1}{762}+1\right)-\frac{761}{139.762}=\)

\(\frac{3}{762}+\frac{761}{139.762}-\frac{761}{139.762}=\frac{3}{762}\)

\(\frac{1}{254}\) nhé!!!

Cho mình bk cách làm bn ơi!

\(M=\dfrac{1252\cdot1}{417\cdot762}-\dfrac{3\cdot3809}{417\cdot762}-\dfrac{4}{417\cdot762}+\dfrac{5}{139}\)

\(=\dfrac{-10164}{417\cdot762}=-\dfrac{1694}{52959}\)

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

= \(\frac{3}{762}+\frac{1}{417.762}-\frac{1}{139}.\left(4+\frac{761}{762}\right)-\frac{4}{417.762}+\frac{5}{139}\)

= \(\frac{3}{762}+\left(\frac{1}{417.762}-\frac{4}{417.762}\right)-\frac{1}{139}.\left(4+1-\frac{1}{762}\right)+\frac{5}{139}\)

= \(\frac{3}{762}+\frac{-3}{417.762}-\frac{5}{139}+\frac{1}{762.139}+\frac{5}{139}\)

= \(\frac{3}{762}+\left(\frac{-1}{139.762}+\frac{1}{762.139}\right)+\left(-\frac{5}{139}+\frac{5}{139}\right)=\frac{3}{762}=\frac{1}{254}\)