9/2

k mình nha

= \(\frac{9}{2}\)

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

\(=\frac{45}{10}=\frac{9}{2}\)

\(=\frac{45}{10}=\frac{9}{2}\)

giúp với ạ

giải dc nhưng mà hoi lâu

a) $\frac{1}{2} - \frac{1}{4} = \frac{2}{4} - \frac{1}{4} = \frac{1}{4}$   

b) $\frac{2}{3} - \frac{4}{{15}} = \frac{{10}}{{15}} - \frac{4}{{15}} = \frac{6}{{15}} = \frac{2}{5}$                       

c) $\frac{3}{5} - \frac{{10}}{{25}} = \frac{{15}}{{25}} - \frac{{10}}{{25}} = \frac{5}{{25}} = \frac{1}{5}$

a,

\(=\frac{1+2+3+4+5+6+7+8+9}{10}=\frac{45}{10}=\frac{9}{2}\)

b,\(=9\times\left(\frac{26\times10101}{27\times10101}+\frac{8\times11111}{9\times11111}\right)=9\times\left(\frac{26}{27}+\frac{8}{9}\right)=9\times\frac{50}{27}=\frac{50}{3}\)

k cho mk nha!!!!!!!!!!!!!

Mk cần gấp các bạn ơi !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!?

a) $\frac{1}{6}:\frac{3}{7} = \frac{1}{6} \times \frac{7}{3} = \frac{7}{{18}}$  

b) $\frac{5}{{12}}:\frac{1}{4} = \frac{5}{{12}} \times \frac{4}{1} = \frac{{5 \times 4}}{{12 \times 1}} = \frac{{5 \times 4}}{{4 \times 3 \times 1}} = \frac{5}{3}$

c) $\frac{4}{{15}}:\frac{8}{3} = \frac{4}{{15}} \times \frac{3}{8} = \frac{{4 \times 3}}{{15 \times 8}} = \frac{{4 \times 3}}{{5 \times 3 \times 4 \times 2}} = \frac{1}{{10}}$          

d) $\frac{{18}}{5}:\frac{9}{{10}} = \frac{{18}}{5} \times \frac{{10}}{9} = \frac{{18 \times 10}}{{5 \times 9}} = \frac{{9 \times 2 \times 5 \times 2}}{{5 \times 9}} = 4$

\(\frac{4}{5}+\left(x:\frac{2}{3}-\frac{1}{2}\right)=\frac{9}{10}\)

\(x:\frac{2}{3}-\frac{1}{2}=\frac{9}{10}-\frac{4}{5}\)

\(x:\frac{2}{3}-\frac{1}{2}=\frac{1}{10}\)

\(x:\frac{2}{3}=\frac{1}{10}-\frac{1}{2}\)

\(x:\frac{2}{3}=\frac{-2}{5}\)

\(x=\frac{-2}{5}X\frac{2}{3}\)

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

\(\frac{4}{5}+\left(x:\frac{2}{3}-\frac{1}{2}\right)=\frac{9}{10}\)

\(x:\frac{2}{3}-\frac{1}{2}=\frac{1}{10}\)

\(x:\frac{2}{3}=\frac{3}{5}\)

\(x=\frac{2}{5}\)

a Đ

b S

c S

d Đ

a ) S 

b ) Đ

c ) S

d ) Đ

k cho mk nhé 

a) $\frac{1}{{10}} + \frac{3}{{10}} = \frac{{1 + 3}}{{10}} = \frac{4}{{10}} = \frac{2}{5}$

b) $\frac{5}{{12}} + \frac{1}{{12}} = \frac{{5 + 1}}{{12}} = \frac{6}{{12}} = \frac{1}{2}$

c) $\frac{3}{2} + \frac{1}{2} = \frac{{3 + 1}}{2} = \frac{4}{2} = 2$