bấm máy tính đi :D

= 27/182 - 1/182

= 26/182 

= 1/7

tổng của hai số lẻ liên tiếp là 636 . Tìm số bé hơn

Bài 1:

\(\frac{3}{7}\cdot\frac{9}{2}-\frac{1}{14}\cdot\frac{1}{13}\)=\(\frac{27}{14}-\frac{1}{14}\cdot\frac{1}{13}\)

                                          = \(\frac{1}{14}\left(27-\frac{1}{3}\right)\)

                                         = \(\frac{1}{14}\cdot\frac{350}{13}\)=\(\frac{25}{13}\)

bài 2:\(\frac{5}{9}\cdot\frac{7}{13}+\frac{5}{9}\cdot\frac{9}{13}\cdot\frac{3}{13}\)= \(\frac{5}{9}\cdot\frac{1}{13}\left(7+9\cdot\frac{3}{13}\right)\)

                                                            = \(\frac{5}{9}\cdot\frac{1}{13}\cdot\frac{94}{13}\)=\(\frac{470}{1521}\)

có j sai xin mn chỉ bảo!

\(\frac{3}{7}.\frac{9}{26}-\frac{1}{14}.\frac{1}{13}\)

\(=\frac{27}{182}-\frac{1}{182}\)

\(=\frac{1}{7}\)

\(\frac{3}{5}.\frac{13}{46}-\frac{1}{10}.\frac{16}{23}\)

\(=\frac{6}{10}.\frac{13}{46}-\frac{1}{10}.\frac{16}{23}\)

\(=\frac{1}{10}.\frac{78}{46}-\frac{1}{10}.\frac{16}{32}\)

\(=\frac{1}{10}\left(\frac{78}{46}-\frac{32}{46}\right)\)

\(=\frac{1}{10}.1=\frac{1}{10}\)

\(\dfrac{3}{7}.\dfrac{9}{36}-\dfrac{1}{14}.\dfrac{1}{13}\)

\(=\dfrac{3.9}{7.36}-\dfrac{1.1}{14.13}\)

\(=\dfrac{3}{28}-\dfrac{1}{182}=\dfrac{37}{364}\)

3/7 . 9/36 - 1/14 . 1/13

= 3/28 - 1/182 

= 37/364

37/364

= 1/10

bài 1 x bằng 0

bài 2 bằng 1/10

\(=\dfrac{27}{7\cdot26}-\dfrac{1}{182}=\dfrac{26}{182}=\dfrac{1}{7}\)