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18 tháng 9 2022

\(\dfrac{7}{10}\times\dfrac{4}{11}=\dfrac{14}{55}\)

18 tháng 9 2022

14/55

a: \(=3\cdot\dfrac{6+14-9}{42}\cdot\dfrac{14}{11}\)

\(=3\cdot\dfrac{11}{42}\cdot\dfrac{14}{11}=1\)

b: \(=\dfrac{19}{5}\cdot\dfrac{11}{10}+\dfrac{9}{5}\cdot\dfrac{7}{3}\)

\(=\dfrac{209}{50}+\dfrac{63}{15}=4.18+4.2=8,38\)

\(=\dfrac{3}{9}\cdot\dfrac{9}{11}\cdot\dfrac{22}{25}\cdot\dfrac{5}{7}\cdot\dfrac{7}{10}=\dfrac{3}{11}\cdot\dfrac{22}{25}\cdot\dfrac{5}{10}=3\cdot2\cdot\dfrac{1}{2}\cdot\dfrac{1}{5}=\dfrac{3}{5}\)

16 tháng 5 2022

\(=\dfrac{3x4x9x11x2x5x7}{4x9x11x5x5x10}=\dfrac{3x2x7}{10}=\dfrac{42}{10}=\dfrac{21}{5}\)

1:

a: =8/7-5/88=669/616

b: \(=1+\dfrac{2}{9}\cdot\dfrac{3}{7}-\dfrac{10}{7}=1+\dfrac{2}{21}-\dfrac{10}{7}\)

\(=\dfrac{21+2-30}{21}=\dfrac{-7}{21}=\dfrac{-1}{3}\)

c: \(=\dfrac{11}{3}-\dfrac{6}{7}+4=\dfrac{77-18+84}{21}=\dfrac{143}{21}\)

Bài 2:

a: =>9/4-x=5/11*2=10/11

=>x=9/4-10/11=59/44

b: =>2/9:x=19/21

=>x=2/9:19/21=14/57

 

3 tháng 12 2017

      \(\frac{7}{10}-\frac{3}{10}x\frac{1}{10}+\frac{4}{25}\)

\(=\frac{7}{10}-\frac{3}{100}+\frac{4}{25}\)

\(=\frac{70}{100}-\frac{3}{100}+\frac{4}{25}\)

\(=\frac{67}{100}+\frac{4}{25}\)

\(=\frac{67}{100}+\frac{16}{100}\)

\(=\frac{83}{100}=0,83\)

      \(\frac{6}{11}x\frac{3}{7}+\frac{3}{7}x\frac{5}{11}\)

\(=\frac{18}{77}+\frac{15}{77}\)

\(=\frac{33}{77}=\frac{3}{7}\)

     \(49x\left(311-4807:23\right)+98210\)

\(=49x\left(311-209\right)+98210\)

\(=49x102+98210\)

\(=4998+98210\)

\(=103208\)

3 tháng 12 2017

a) \(\frac{7}{10}-\frac{3}{10}\times\frac{1}{10}+\frac{4}{25}\)

\(=\frac{2}{5}\times\frac{1}{10}+\frac{4}{25}\)

\(=\frac{1}{25}+\frac{4}{25}\)

\(=\frac{5}{25}=\frac{1}{5}\)

b)\(\frac{6}{11}\times\frac{3}{7}+\frac{3}{7}\times\frac{5}{11}\)

\(=\frac{3}{7}\times\left(\frac{6}{11}+\frac{5}{11}\right)\)

\(=\frac{3}{7}\times1\)

\(=\frac{3}{7}\)

c)\(49\times\left(311-4807:23\right)+98210\)

\(=49\times\left(311-209\right)+98210\)

\(=49\times102+98210\)

\(=4998+98210\)

\(=103208\)

17 tháng 7 2019

(6:3/5-7/6×6/7) : (21/5×10/11+57/11)

=(10-1):(42/11+57/11)

=9:9

=1

17 tháng 7 2019

(6:3/5-7/6x6/7):(21/5x10/11+57/11)

= (10-1):(42/11+57/11)

=9:9

=1

~~~~ Hoc tot ~~~~~

2. \(7\left(-3\right)-5\left(3-x\right)=11-5\)

\(\Leftrightarrow-21-5\left(3-x\right)=6\)

\(\Leftrightarrow-5\left(3-x\right)=27\)

\(\Leftrightarrow3-x=-\frac{27}{5}\)

\(\Leftrightarrow x=-\frac{42}{5}\)

Vậy \(x=-\frac{42}{5}\) 

Khó quá :((

1 tháng 7 2018

a,  -3/4 + 3/7 + -1/4 + 4/9 + 4/7

=\(\left(\frac{-3}{4}+\frac{-1}{4}\right)+\left(\frac{3}{7}+\frac{4}{7}\right)+\frac{4}{9}\)

=\(-1+1+\frac{4}{9}\)

=\(\frac{4}{9}\)

b, -7/9 x 4/11 + -7/9 x 7/11 + 5 và 7/9 

\(=\frac{7}{9}x\frac{-4}{11}+\frac{7}{9}x\frac{-7}{11}+5x\frac{7}{9}\)

\(=\frac{7}{9}x\left(\frac{-4}{11}+\frac{-7}{11}+5\right)\)

\(=\frac{7}{9}x4\)

\(=\frac{28}{9}\)

c, ( 21/31 + 2013/6039 ) - ( 44/53 - 10/31) - /53

20 tháng 8 2023

\(a.\dfrac{1}{2}:3+x=\dfrac{14}{5}\)

\(\dfrac{1}{6}+x=\dfrac{14}{5}\)

\(=>x=\dfrac{79}{30}\)

\(b.\dfrac{8}{5}:x:\dfrac{7}{4}=\dfrac{11}{6}\)

\(\left(\dfrac{8}{5}\cdot\dfrac{4}{7}\right):x=\dfrac{11}{6}\)

\(\dfrac{32}{35}:x=\dfrac{11}{6}\)

\(x=\dfrac{192}{385}\)

\(c.\dfrac{24}{10}+x:\dfrac{3}{4}=\dfrac{11}{3}\)

\(x:\dfrac{3}{4}=\dfrac{11}{3}-\dfrac{24}{10}\)

\(x:\dfrac{3}{4}=\dfrac{38}{30}\)

\(=>x=\dfrac{19}{20}\)

HQ
Hà Quang Minh
Giáo viên
20 tháng 8 2023

\(a,\dfrac{1}{2}:3+x=\dfrac{14}{5}\\ \Leftrightarrow x+\dfrac{1}{6}=\dfrac{14}{5}\\ \Leftrightarrow x=\dfrac{79}{30}\\ b,\dfrac{8}{5}:x:\dfrac{7}{4}=\dfrac{11}{6}\\ \Leftrightarrow x=\dfrac{192}{385}\\ c,\dfrac{24}{10}+x:\dfrac{3}{4}=\dfrac{11}{3}\\ \Leftrightarrow\dfrac{4}{3}x=\dfrac{19}{15}\\ \Leftrightarrow x=\dfrac{19}{20}\)