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6 tháng 8 2023

\(\dfrac{1}{2}+\dfrac{1}{3}-\dfrac{1}{5}=\dfrac{3+2}{6}-\dfrac{1}{5}=\dfrac{5}{6}-\dfrac{1}{5}=\dfrac{5\times5-6}{30}=\dfrac{19}{30}\\ \dfrac{1}{5}:4+\dfrac{3}{4}=\dfrac{1}{5}\times4+\dfrac{3}{4}=\dfrac{4}{5}+\dfrac{3}{4}=\dfrac{4\times4+3\times5}{20}=\dfrac{31}{20}\)

\(\dfrac{4}{3}\times\dfrac{9}{5}-\dfrac{3}{10}=\dfrac{36}{15}-\dfrac{3}{10}=\dfrac{12}{5}-\dfrac{3}{10}=\dfrac{12\times2-3}{10}=\dfrac{21}{10}\)

6 tháng 8 2023

\(\dfrac{1}{2}\) + \(\dfrac{1}{3}\) - \(\dfrac{1}{5}\)

\(\dfrac{1\times15}{2\times15}\) + \(\dfrac{1\times10}{3\times10}\) - \(\dfrac{1\times6}{5\times6}\)

\(\dfrac{15}{30}\) + \(\dfrac{10}{30}\) - \(\dfrac{6}{30}\)

\(\dfrac{19}{30}\)

  \(\dfrac{1}{5}\) : 4 + \(\dfrac{3}{4}\)

\(\dfrac{1}{5}\) \(\times\) \(\dfrac{1}{4}\) + \(\dfrac{3}{4}\)

\(\dfrac{1}{20}\) + \(\dfrac{3\times5}{4\times5}\)

\(\dfrac{1}{20}+\dfrac{15}{20}\)

\(\dfrac{16}{20}\)

\(\dfrac{4}{5}\) 

   \(\dfrac{4}{3}\) \(\times\) \(\dfrac{9}{5}\) - \(\dfrac{3}{10}\) 

=  \(\dfrac{12}{5}\) - \(\dfrac{3}{10}\)

\(\dfrac{24}{10}\) - \(\dfrac{3}{10}\)

\(\dfrac{21}{10}\)

27 tháng 4 2022

1)

 a)\(\dfrac{20}{30}+\dfrac{9}{30}=\dfrac{29}{30}\)

b)\(\dfrac{16}{24}-\dfrac{15}{24}=\dfrac{1}{24}\)

c)\(\dfrac{12}{63}=\dfrac{4}{21}\)

d) \(\dfrac{5}{6}x\dfrac{3}{4}=\dfrac{15}{24}=\dfrac{5}{8}\)

2)

a)\(x=\dfrac{5}{4}-\dfrac{2}{3}\)

\(x=\dfrac{7}{12}\)

 

b) \(x=4x\dfrac{3}{5}\)

\(x=\dfrac{12}{5}\)

 

27 tháng 4 2022

CẢM ƠN NHA

4 tháng 3 2023

\(\dfrac{2}{5}\times\dfrac{3}{4}-\dfrac{1}{8}=\dfrac{1}{5}\times\dfrac{3}{2}-\dfrac{1}{8}=\dfrac{3}{10}-\dfrac{1}{8}=\dfrac{24}{80}-\dfrac{10}{80}=\dfrac{14}{80}=\dfrac{7}{40}\\ \dfrac{4}{3}+\dfrac{1}{3}-\dfrac{1}{5}=\dfrac{5}{3}-\dfrac{1}{5}=\dfrac{25}{15}-\dfrac{3}{15}=\dfrac{22}{15}\\ \dfrac{9}{20}-\dfrac{3}{5}\times\dfrac{1}{4}=\dfrac{9}{20}-\dfrac{3}{20}=\dfrac{6}{20}=\dfrac{3}{10}\\ \dfrac{2}{8}+\dfrac{2}{3}:\dfrac{4}{5}=\dfrac{2}{8}+\dfrac{2}{3}\times\dfrac{5}{4}=\dfrac{2}{8}+\dfrac{1}{3}\times\dfrac{5}{2}=\dfrac{2}{8}+\dfrac{5}{6}=\dfrac{1}{4}+\dfrac{5}{6}=\dfrac{6}{24}+\dfrac{20}{24}=\dfrac{26}{24}=\dfrac{13}{12}\)

3 tháng 3 2022

Mình đang cần gấp!☹

3 tháng 3 2022

Đ V T Hucche

21 tháng 4 2022

ét ô ét

 

12 tháng 11 2022

a.25/27                                                                                                                 b.0                          c.0

24 tháng 2 2022

a, \(=\dfrac{1+4}{5}+\dfrac{5+1+3}{9}=1+1=2\)

b, \(=\dfrac{1+4+2}{3}+\dfrac{1+2+5}{6}=\dfrac{6}{3}+\dfrac{8}{6}=2+\dfrac{4}{3}=\dfrac{6+4}{3}=\dfrac{10}{3}\)

24 tháng 2 2022

cảm ơn bạn nha

3 tháng 3 2023

a)

`2/3+5/2-3/4`

`=10/4-3/4+2/3`

`=7/4+2/3`

`=21/12+8/12`

`=29/12`

b)

`2/5xx1/2:1/3`

`=2/10xx3/1`

`=6/10=3/5`

c)

`2/9:2/9xx1/3`

`=2/9xx9/2xx1/3`

`=1xx1/3`

`=1/3`

3 tháng 3 2023

a, \(\dfrac{2}{3}\) + \(\dfrac{5}{2}\) - \(\dfrac{3}{4}\)

\(\dfrac{8}{12}\) + \(\dfrac{30}{12}\) - \(\dfrac{9}{12}\)

\(\dfrac{38-9}{12}\)

\(\dfrac{29}{12}\)

b, \(\dfrac{2}{5}\) x \(\dfrac{1}{2}\) : \(\dfrac{1}{3}\)

\(\dfrac{1}{5}\) x \(\dfrac{3}{1}\)

\(\dfrac{3}{5}\)

c, \(\dfrac{2}{9}\) : \(\dfrac{2}{9}\) x \(\dfrac{1}{3}\)

= 1 x \(\dfrac{1}{3}\)

\(\dfrac{1}{3}\)

24 tháng 8 2023

a) \(1+\dfrac{4}{9}=\dfrac{9}{9}+\dfrac{4}{9}=\dfrac{9+4}{9}=\dfrac{13}{9}\)

b) \(5+\dfrac{1}{2}=\dfrac{10}{2}+\dfrac{1}{2}=\dfrac{10+1}{2}=\dfrac{11}{2}\)

c) \(3-\dfrac{5}{6}=\dfrac{18}{6}-\dfrac{5}{6}=\dfrac{18-5}{6}=\dfrac{13}{6}\)

d) \(\dfrac{31}{7}-2=\dfrac{31}{7}-\dfrac{14}{7}=\dfrac{31-14}{7}=\dfrac{17}{7}\)

8 tháng 5 2022

bài 1

a)\(=\dfrac{16}{40}+\dfrac{15}{40}=\dfrac{31}{40}\)

b)\(=\dfrac{7}{6}-\dfrac{4}{6}=\dfrac{3}{6}=\dfrac{1}{2}\)

c)\(=\dfrac{30}{9}=\dfrac{10}{3}\)

d)\(=\dfrac{8}{5}\times\dfrac{7}{4}=\dfrac{56}{20}=\dfrac{14}{5}\)

8 tháng 5 2022

bài 2

a)\(x=\dfrac{5}{6}-\dfrac{4}{5}=\dfrac{25}{30}-\dfrac{24}{30}=\dfrac{1}{30}\)

b)\(x=5\times\dfrac{10}{7}=\dfrac{50}{7}\)

bài 4 :

145 ×× 69 + 22 x  145 +145 x 8 + 145 

\(=145\times\left(69+22+8+1\right)=145\times100=14500\)

 

29 tháng 10 2023

\(\dfrac{1}{3}+\dfrac{2}{9}=\dfrac{3}{3\times3}+\dfrac{2}{9}=\dfrac{3}{9}+\dfrac{2}{9}=\dfrac{5}{9}\)

\(\dfrac{1}{2}+\dfrac{3}{8}=\dfrac{4}{2\times4}+\dfrac{3}{8}=\dfrac{4}{8}+\dfrac{3}{8}=\dfrac{7}{8}\)

\(\dfrac{5}{12}+\dfrac{2}{3}=\dfrac{5}{12}+\dfrac{2\times4}{3\times4}=\dfrac{5}{12}+\dfrac{8}{12}=\dfrac{13}{12}\)

\(\dfrac{5}{16}+\dfrac{3}{8}=\dfrac{5}{16}+\dfrac{3\times2}{8\times2}=\dfrac{5}{16}+\dfrac{6}{16}=\dfrac{11}{16}\)

\(\dfrac{4}{15}+\dfrac{3}{5}=\dfrac{4}{15}+\dfrac{3\times3}{5\times3}=\dfrac{4}{15}+\dfrac{9}{15}=\dfrac{13}{15}\)

\(\dfrac{8}{63}+\dfrac{7}{10}=\dfrac{8\times10}{63\times10}+\dfrac{7\times63}{10\times63}=\dfrac{80}{630}+\dfrac{441}{630}=\dfrac{521}{630}\)