a) $\frac{{14}}{{18}}:\frac{8}{9} = \frac{7}{9}:\frac{8}{9} = \frac{7}{9} \times \frac{9}{8} = \frac{{63}}{{72}} = \frac{7}{8}$

b) $\frac{9}{6}:\frac{3}{{10}} = \frac{3}{2}:\frac{3}{{10}} = \frac{3}{2} \times \frac{{10}}{3} = \frac{{30}}{6} = 5$

c) $\frac{4}{5}:\frac{{10}}{{15}} = \frac{4}{5}:\frac{2}{3} = \frac{4}{5} \times \frac{3}{2} = \frac{{12}}{{10}} = \frac{6}{5}$

d)  $\frac{1}{6}:\frac{{21}}{9} = \frac{1}{6}:\frac{7}{3} = \frac{1}{6} \times \frac{3}{7} = \frac{3}{{42}} = \frac{1}{{14}}$

\(1-\left(\frac{12}{5}+y=\frac{8}{9}\right):\frac{16}{9}=0\)

\(1-\left(\frac{12}{5}+y-\frac{8}{9}\right)=0\times\frac{16}{9}\)

\(1-\left(\frac{12}{5}+y-\frac{8}{9}\right)=0\)

\(\frac{12}{5}+y-\frac{8}{9}=1-0\)

\(\frac{12}{5}-y+\frac{8}{9}=1\)

\(\frac{12}{5}-y=1-\frac{8}{9}\)

\(\frac{12}{5}-y=\frac{1}{9}\)

\(y=\frac{12}{5}-\frac{1}{9}\)

\(y=\frac{108}{45}-\frac{5}{45}\)

\(y=\frac{103}{45}\)

\(\frac{1}{2}:\frac{3}{2}:\frac{5}{4}:\frac{6}{5}:\frac{7}{6}:\frac{8}{7}\)

\(=\frac{1}{2}\cdot\frac{2}{3}\cdot\frac{4}{5}\cdot\frac{5}{6}\cdot\frac{6}{7}\cdot\frac{7}{8}\)

\(=\frac{1\cdot\left(2\cdot5\cdot6\cdot7\right)}{8\cdot3\cdot\left(2\cdot5\cdot6\cdot7\right)}\)

\(=\frac{1}{24}\)

\(\frac{1}{2}\cdot\frac{2}{3}\cdot\frac{3}{4}\cdot\frac{4}{5}\cdot\frac{5}{6}\cdot\frac{6}{7}\cdot\frac{7}{8}\cdot\frac{8}{9}\cdot\frac{9}{10}\)

\(=\frac{1\cdot\left(2\cdot3\cdot4\cdot5\cdot6\cdot7\cdot8\cdot9\right)}{\left(2\cdot3\cdot4\cdot5\cdot6\cdot7\cdot8\cdot9\right)\cdot10}\)

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

Ta có: \(\frac56=1-\frac16;\frac78=1-\frac18;\frac{9}{10}=1-\frac{1}{10}\)

Ta có: 6<8<10

=>\(\frac16>\frac18>\frac{1}{10}\)

=>\(-\frac16<-\frac18<-\frac{1}{10}\)

=>\(-\frac16+1<-\frac18+1<-\frac{1}{10}+1\)

=>\(\frac56<\frac78<\frac{9}{10}\) <1

mà \(1=\frac88;1=\frac55<\frac65\)

nên \(\frac56<\frac78<\frac{9}{10}<\frac88<\frac65\)

M = (345 x (6789 + 3456 - 245)/690) x 99/100 x 98/99 x...x 2/3 x 1/2
M = ((345 x 10000)/690) x 99/2 (rút gọn)
M = (10000/2) x 99/2
M = 5000 x 99/2
M = 247500
Ok nha

mình k cho ai nhanh nhất

\(\frac{2}{5}+52\) ak bạn

Tổng của 3 phân số là:

     (23/20+7/20+21/20):2=37/10

Phân số thứ nhất là:

    37/10-7/20=67/20

Phân số thứ hai là:

   37/10-21/20=53/20

Phân số thứ ba là:

    37/10-23/20=51/20

                  Đáp số : phân số thứ 1:67/20

                               phân số thứ 2

                               phân số thứ 3

Đáp số: phân số thứ 1 : 67/20

            phân số thứ 2 : 53/20

            phân số thứ 3 : 51/20

Chúc bạn học giỏi!

\(x+\frac{2}{3}=\frac{9}{11}\)

\(x=\frac{9}{11}-\frac{2}{3}\)

\(x=\frac{5}{33}\)

\(x-\frac{3}{10}=\frac{4}{15}\)

\(x=\frac{3}{10}-\frac{4}{15}\)

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

\(x\times\frac{1}{7}=\frac{5}{6}\)

\(x=\frac{5}{6}:\frac{1}{7}\)

\(x=\frac{35}{6}\)

\(x:\frac{3}{5}=\frac{1}{6}\)

\(x=\frac{3}{5}.\frac{1}{6}\)

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

+, \(x+\frac{2}{3}=\frac{9}{11}\)

\(x=\frac{9}{11}-\frac{2}{3}=\frac{5}{33}\)

+, \(x-\frac{3}{10}=\frac{4}{15}\)

\(x=\frac{4}{15}+\frac{3}{10}=\frac{17}{30}\)

+, \(x\cdot\frac{1}{7}=\frac{5}{6}\)

\(x=\frac{5}{6}:\frac{1}{7}=\frac{5}{6}.\frac{7}{1}=\frac{35}{6}\)

+,\(x:\frac{3}{5}=\frac{1}{6}\)

\(x=\frac{1}{6}\cdot\frac{3}{5}=\frac{3}{30}=\frac{1}{10}\)

1) \(\frac{4}{5}.\frac{8}{3}.\frac{x}{7}=\frac{96}{105}\)

\(\frac{32.x}{105}=\frac{96}{105}\)

\(32x=96\)

\(x=3\)

Bài 1: Tìm \(x\)

\(\frac45\times\frac83\times\) \(\frac{x}{7}\) = \(\frac{96}{105}\)

\(\frac{32}{15}\) x \(\frac{x}{7}\) = \(\frac{32}{35}\)

\(\frac{x}{7}\) = \(\frac{32}{35}\) : \(\frac{32}{15}\)

\(\frac{x}{7}\) = \(\frac{32}{35}\) x \(\frac{15}{32}\)

\(\frac{x}{7}\) = \(\frac37\)

\(x=\frac37\times7\)

\(x=3\)

b; \(\frac74\times\frac{3}{x}\times\) \(\frac{11}{5}\) = \(\frac{231}{200}\)

\(\frac74\) x \(\frac{3}{x}\) = \(\frac{231}{200}\) : \(\frac{11}{5}\)

\(\frac74\times\frac{3}{x}\) = \(\frac{231}{200}\) x \(\frac{5}{11}\)

\(\frac74\) x \(\frac{3}{x}\) = \(\frac{21}{40}\)

\(\frac{3}{x}\) = \(\frac{21}{40}\) : \(\frac74\)

\(\frac{3}{x}\) = \(\frac{21}{40}\) x \(\frac47\)

\(\frac{3}{x}\) = \(\frac{3}{10}\)

\(x=3:\frac{3}{10}\)

\(x=3\times\frac{3}{10}\)

\(x=10\)