Tìm x hả, đây nha em:

x.3/7=9/14

     x=9/14 : 3/7

     x=9/14.7/3

     x=63/42 ta rút gọn =3/2

  Vậy x=3/2 nha , nhớ k ^.^

a; -\(\dfrac{4}{9}.\dfrac{7}{15}+\dfrac{4}{-9}.\dfrac{8}{15}\)

= - \(\dfrac{4}{9}\).(\(\dfrac{7}{15}+\dfrac{8}{15}\))

= - \(\dfrac{4}{9}\).1

= - \(\dfrac{4}{9}\)

b; - \(\dfrac{5}{4}.\dfrac{16}{25}\) + \(\dfrac{-5}{4}\).\(\dfrac{9}{25}\)

= - \(\dfrac{5}{4}\).(\(\dfrac{16}{25}\) + \(\dfrac{9}{25}\))

= - \(\dfrac{5}{4}\). 1

= - \(\dfrac{5}{4}\)

c; \(-\dfrac{5}{12}.\dfrac{4}{19}\) + \(\dfrac{-7}{12}.\dfrac{4}{19}-\dfrac{40}{57}\)

= - \(\dfrac{5}{12}\).\(\dfrac{4}{19}\) - \(\dfrac{7}{12}\).\(\dfrac{4}{19}\) - \(\dfrac{4}{19}\).\(\dfrac{10}{3}\)

= - \(\dfrac{4}{19}\).(\(\dfrac{5}{12}\) + \(\dfrac{7}{12}\) + \(\dfrac{10}{3}\))

= - \(\dfrac{4}{19}\).\(\dfrac{13}{3}\)

= - \(\dfrac{52}{57}\)

\(\frac{7}{8}-\frac{7}{16}-\frac{11}{32}\)

= \(\frac{28}{32}-\frac{14}{32}-\frac{11}{32}\)

= \(\frac{28-14-11}{32}\)

= \(\frac{3}{32}\)

Đề : 7/8 - 7/16 - 11/32 = ?

Chọn MSC là 32 . Ta có phép tính : 28/32 - 14/32 - 11/32 = 3/32 

Tíc nha !

\(\frac{7}{8}-\frac{7}{16}-\frac{11}{32}=\frac{7}{16}-\frac{11}{32}=\frac{3}{32}=0,09375\)

\(3\frac{1}{2}+4\frac{5}{7}-5\frac{5}{14}=\frac{7}{2}+\frac{33}{7}-\frac{75}{14}=\frac{49}{14}+\frac{66}{14}-\frac{75}{14}=\frac{40}{14}=\frac{20}{7}\)

#Fox

=20/7

Bạn chỉ giúp mk cách làm được ko ạ

20/7 nha

  \(\dfrac{3}{4}\cdot\dfrac{2}{5}-\dfrac{3}{4}\cdot\dfrac{2}{7}\)

= \(\dfrac{3}{4}\cdot\left(\dfrac{2}{5}-\dfrac{2}{7}\right)\)

= \(\dfrac{3}{4}\cdot\left(\dfrac{14}{35}-\dfrac{10}{35}\right)\)

= \(\dfrac{3}{4}\cdot\dfrac{4}{35}\)

= \(\dfrac{3}{35}\)

\(\dfrac{7}{16}-\dfrac{3}{8}=\dfrac{7}{16}-\dfrac{6}{16}=\dfrac{1}{16}\)

1/16

Bằng 1 phần 16 nha

=12/7.3/4

=9/7

\(1\frac{5}{7}\)x \(\frac{3}{4}\)

= \(\frac{12}{7}\)x \(\frac{3}{4}\)

= \(\frac{36}{28}=\frac{9}{7}\)

đ/s:\(\frac{9}{7}\)

16 phần 21

16 phần 21 bạn nhé

16 phần 21