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23 tháng 8 2017

1. \(\dfrac{16.17-5}{16.16-1}:\left(x-\dfrac{2}{3}\right)=\dfrac{1}{3}\)

<=> \(\dfrac{272-5}{256-1}:\left(x-\dfrac{2}{3}\right)=\dfrac{1}{3}\)

<=> \(\dfrac{267}{255}:\left(x-\dfrac{2}{3}\right)=\dfrac{1}{3}\)
<=> x - \(\dfrac{2}{3}=\dfrac{267}{85}\)

<=> x = \(\dfrac{971}{255}\)

@Triều Nguyễn Quốc

23 tháng 8 2017

2. a, 8\(\dfrac{1}{5}\left(11\dfrac{94}{1591}-6\dfrac{38}{1517}\right):8\dfrac{11}{13}\)

= \(\dfrac{41}{5}\left(5\dfrac{60}{1763}\right):\dfrac{355}{43}\)

= \(\dfrac{41}{5}.\dfrac{8875}{1763}:\dfrac{355}{43}\)
= \(\dfrac{1775}{43}:\dfrac{355}{43}\)

= 5

@Triều Nguyễn Quốc

AH
Akai Haruma
Giáo viên
17 tháng 4 2023

Lời giải:
a.

$x=\frac{-5}{6}-\frac{2}{3}=\frac{-3}{2}$

b.

$\frac{2}{3}x=\frac{1}{10}-\frac{1}{2}=\frac{-2}{5}$

$x=\frac{-2}{5}: \frac{2}{3}=\frac{-3}{5}$

c.

$\frac{7}{8}x=\frac{2}{9}-\frac{1}{3}=\frac{-1}{9}$
$x=\frac{-1}{9}: \frac{7}{8}=\frac{-8}{63}$

 

 

AH
Akai Haruma
Giáo viên
17 tháng 4 2023

d.

$\frac{5}{7}: x=\frac{1}{6}-\frac{4}{5}=\frac{-19}{30}$

$x=\frac{5}{7}: \frac{-19}{30}=\frac{-150}{133}$

e.

$(\frac{2}{5}-1\frac{2}{3}):x=\frac{2}{5}+\frac{3}{5}=1$

$\frac{-19}{15}: x=1$

$x=\frac{-19}{15}:1 =\frac{-19}{15}$

f.

$(-\frac{3}{4}+x).2\frac{2}{3}=1$

$\frac{-3}{4}+x=1: 2\frac{2}{3}=\frac{3}{8}$

$x=\frac{3}{8}+\frac{3}{4}=\frac{9}{8}$

1 tháng 4 2018

\(N=8\dfrac{1}{5}\left(11\dfrac{94}{1591}-6\dfrac{38}{1517}\right):8\dfrac{11}{43}\)

\(N=\dfrac{41}{5}\left(\dfrac{17595}{1591}-\dfrac{9140}{1517}\right):\dfrac{355}{43}\)

\(N=\dfrac{41}{5}.\dfrac{8875}{1763}:\dfrac{355}{43}\)

\(N=\dfrac{1775}{43}:\dfrac{355}{43}\)

\(N=5.\)

31 tháng 7 2017

Trời ơi cái đề bài !!!

Thoy thì làm từng câu vậy

a) \(I=10101.\left(\dfrac{5}{111111}+\dfrac{5}{222222}-\dfrac{4}{111111}\right)\)

\(I=10101.\left(\dfrac{10}{222222}+\dfrac{5}{222222}-\dfrac{8}{222222}\right)\)

\(I=10101.\left(\dfrac{15}{222222}-\dfrac{8}{222222}\right)\)

\(I=10101.\dfrac{7}{222222}\)

\(I=\dfrac{7}{22}\)

31 tháng 7 2017

1.

a) \(A=10101\left(\dfrac{5}{111111}+\dfrac{5}{222222}-\dfrac{4}{3.7.11.13.37}\right)\)\(A=\dfrac{10101.5}{10101.11}+\dfrac{10101.5}{10101.22}-\dfrac{10101.4}{10101.11}\)

\(A=\dfrac{5}{11}+\dfrac{5}{22}-\dfrac{4}{11}=\dfrac{7}{22}\)

11 tháng 2 2022

Bài 1 : 

\(=\dfrac{2}{11}+\dfrac{4}{11}-\dfrac{6}{11}-\dfrac{3}{8}-\dfrac{5}{8}=0-1=-1\)

Bài 2 : 

\(\Rightarrow3+x=8\Leftrightarrow x=5\)

Bài 3 : 

\(\Leftrightarrow x-\dfrac{5}{11}=\dfrac{5}{4}\Leftrightarrow x=\dfrac{35}{44}\)

Bài 4 : 

Trong 2 ngày An đọc được số quyên phần quyên sách 

\(\dfrac{1}{11}+\dfrac{8}{11}=\dfrac{9}{11}\)( quyển sách ) 

đs : 9/11 quyển sách 

18 tháng 5 2017

\(M=\dfrac{120-\dfrac{1}{2}.40.5.\dfrac{1}{5}.20.\dfrac{1}{4}-20}{1+5+....+41}\\ =\dfrac{120-20.5-20}{1+5+...+41}\\ =\dfrac{0}{1+5+...+41}\\ =0\)

\(N=10101\left(\dfrac{6}{3.7.11.13.37}+\dfrac{6}{2.3.7.11.13.37}-\dfrac{7}{3.7.11.13.37}\right)\\ =10101\left(-\dfrac{2}{2.3.7.11.13.37}+\dfrac{6}{2.3.7.11.13.37}\right)\\ =3.7.13.37\left(\dfrac{4}{2.3.7.11.13.37}\right)=\dfrac{4}{2.11}=\dfrac{2}{11}\)

21 tháng 5 2017

giỏi z đạt - thánh toán học

28 tháng 4 2017

Bài 1:

a) \(\left(\dfrac{3}{8}+\dfrac{-3}{4}+\dfrac{7}{12}\right):\dfrac{5}{6}+\dfrac{1}{2}\)

\(=\left(\dfrac{9}{24}+\dfrac{-18}{24}+\dfrac{14}{24}\right):\dfrac{5}{6}+\dfrac{1}{2}\)

\(=\dfrac{5}{24}:\dfrac{5}{6}+\dfrac{1}{2}\)

\(=\dfrac{5}{24}.\dfrac{6}{5}+\dfrac{1}{2}\)

\(=\dfrac{1}{4}+\dfrac{1}{2}\)

\(=\dfrac{1}{4}+\dfrac{2}{4}\)

\(=\dfrac{3}{4}\)

b) \(\dfrac{1}{2}+\dfrac{3}{4}-\left(\dfrac{3}{4}-\dfrac{4}{5}\right)\)

\(=\dfrac{1}{2}+\dfrac{3}{4}-\dfrac{3}{4}+\dfrac{4}{5}\)

\(=\left(\dfrac{1}{2}+\dfrac{4}{5}\right)+\left(\dfrac{3}{4}-\dfrac{3}{4}\right)\)

\(=\dfrac{1}{2}+\dfrac{4}{5}\)

\(=\dfrac{5}{10}+\dfrac{8}{10}\)

\(=\dfrac{9}{5}\)

c) \(6\dfrac{5}{12}:2\dfrac{3}{4}+11\dfrac{1}{4}.\left(\dfrac{1}{3}+\dfrac{1}{5}\right)\)

\(=\dfrac{77}{12}:\dfrac{11}{4}+\dfrac{42}{4}.\left(\dfrac{1}{3}+\dfrac{1}{5}\right)\)

\(=\dfrac{77}{12}.\dfrac{4}{11}+\dfrac{42}{4}.\left(\dfrac{5}{15}+\dfrac{3}{15}\right)\)

\(=\dfrac{7}{3}+\dfrac{42}{4}.\dfrac{8}{15}\)

\(=\dfrac{7}{3}+\dfrac{14.2}{1.3}\)

\(=\dfrac{7}{3}+\dfrac{28}{3}\)

\(=\dfrac{35}{3}\)

d) \(\left(\dfrac{7}{8}-\dfrac{3}{4}\right).1\dfrac{1}{3}-\dfrac{2}{7}.\left(3,5\right)^2\)

\(=\left(\dfrac{7}{8}-\dfrac{6}{8}\right).\dfrac{4}{3}-\dfrac{2}{7}.12\dfrac{1}{4}\)

\(=\dfrac{1}{8}.\dfrac{4}{3}-\dfrac{2}{7}.\dfrac{49}{4}\)

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

\(=\dfrac{1}{6}-\dfrac{21}{6}\)

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

e) \(\left(\dfrac{3}{5}+0,415-\dfrac{3}{200}\right).2\dfrac{2}{3}.0,25\)

\(=\left(\dfrac{3}{5}+\dfrac{83}{200}-\dfrac{3}{200}\right).\dfrac{8}{3}.\dfrac{1}{4}\)

\(=\left(\dfrac{120}{200}+\dfrac{83}{200}-\dfrac{3}{200}\right).\dfrac{8}{3}.\dfrac{1}{4}\)

\(=1.\dfrac{8}{3}.\dfrac{1}{4}\)

\(=\dfrac{2}{3}\)

f) \(\dfrac{5}{16}:0,125-\left(2\dfrac{1}{4}-0,6\right).\dfrac{10}{11}\)

\(=\dfrac{5}{16}:\dfrac{1}{8}-\left(\dfrac{9}{4}-\dfrac{3}{5}\right).\dfrac{10}{11}\)

\(=\dfrac{5}{16}.\dfrac{8}{1}-\left(\dfrac{45}{20}-\dfrac{12}{20}\right).\dfrac{10}{11}\)

\(=\dfrac{5}{2}-\dfrac{33}{20}.\dfrac{10}{11}\)

\(=\dfrac{5}{2}-\dfrac{3}{2}\)

\(=\dfrac{2}{2}=1\)

g) \(0,25:\left(10,3-9,8\right)-\dfrac{3}{4}\)

\(=\dfrac{1}{4}:\dfrac{1}{2}-\dfrac{3}{4}\)

\(=\dfrac{1}{4}.\dfrac{2}{1}-\dfrac{3}{4}\)

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

\(=\dfrac{2}{4}-\dfrac{3}{4}\)

\(=\dfrac{-1}{4}\)

h) \(1\dfrac{13}{15}.0,75-\left(\dfrac{11}{20}+20\%\right):\dfrac{7}{3}\)

\(=\dfrac{28}{15}.\dfrac{3}{4}-\left(\dfrac{11}{20}+\dfrac{1}{5}\right):\dfrac{7}{3}\)

\(=\dfrac{7}{5}-\left(\dfrac{11}{20}+\dfrac{4}{20}\right):\dfrac{7}{3}\)

\(=\dfrac{7}{5}-\dfrac{3}{4}:\dfrac{7}{3}\)

\(=\dfrac{7}{5}-\dfrac{9}{28}\)

\(=\dfrac{196}{140}-\dfrac{45}{140}\)

\(=\dfrac{151}{140}\)

i) \(\dfrac{\left(\dfrac{1}{2-0,75}\right).\left(0,2-\dfrac{2}{5}\right)}{\dfrac{5}{9}-1\dfrac{1}{12}}\)

\(=\dfrac{\left(\dfrac{1}{1,25}\right).\left(\dfrac{1}{5}-\dfrac{2}{5}\right)}{\dfrac{5}{9}-\dfrac{13}{12}}\)

\(=\dfrac{\dfrac{1}{1,25}.\dfrac{-1}{5}}{\dfrac{20}{36}-\dfrac{39}{36}}\)

\(=\dfrac{\dfrac{-1}{6,25}}{\dfrac{-19}{36}}\)

k) \(\dfrac{\dfrac{2}{3}+\dfrac{2}{7}-\dfrac{1}{14}}{-1-\dfrac{3}{7}+\dfrac{3}{28}}\)

\(=\dfrac{\dfrac{2}{3}+\dfrac{2}{7}-\dfrac{2}{28}}{-\dfrac{3}{3}-\dfrac{3}{7}+\dfrac{3}{28}}\)

\(=\dfrac{2\left(\dfrac{1}{3}+\dfrac{1}{7}-\dfrac{1}{28}\right)}{\left(-3\right)\left(\dfrac{1}{3}+\dfrac{1}{7}-\dfrac{1}{28}\right)}\)

\(=-\dfrac{2}{3}\)

29 tháng 4 2017

\(A=0,7.2\dfrac{2}{3}.20.0,375.\dfrac{5}{28}\)

\(A=\dfrac{7}{10}.\dfrac{8}{3}.20.\dfrac{3}{8}.\dfrac{5}{28}\)

\(A=\left(\dfrac{7}{10}.\dfrac{5}{28}\right).\left(\dfrac{8}{3}.\dfrac{3}{8}\right).20\)

\(A=\dfrac{1}{8}.1.20\)

\(A=\dfrac{20}{8}=\dfrac{5}{2}\)

\(B=\left(9\dfrac{30303}{80808}+7\dfrac{303030}{484848}\right)+4,03\)

\(B=\left(9\dfrac{3}{8}+7\dfrac{5}{8}\right)+4,03\)

\(B=\left[\left(9+7\right)+\left(\dfrac{3}{8}+\dfrac{5}{8}\right)\right]+4,03\)

\(B=\left(16+1\right)+4,03\)

\(B=17+4,03\)

\(B=21,03\)

\(C=\left(9,75.21\dfrac{3}{7}+\dfrac{39}{4}.18\dfrac{4}{7}\right).\dfrac{15}{78}\)

\(C=\left(\dfrac{39}{4}.\dfrac{150}{7}+\dfrac{39}{4}.\dfrac{130}{7}\right).\dfrac{15}{78}\)

\(C=\dfrac{39}{4}.\left(\dfrac{150}{7}+\dfrac{130}{7}\right).\dfrac{15}{78}\)

\(C=\dfrac{39}{4}.40.\dfrac{15}{78}\)

\(C=390.\dfrac{15}{78}\)

\(C=75\)

31 tháng 3 2017

\(10101\cdot\left(\dfrac{5}{111111}+\dfrac{5}{222222}-\dfrac{4}{3\cdot7\cdot11\cdot13\cdot37}\right)\)=\(10101\cdot\left(\dfrac{5}{111111}+\dfrac{5}{222222}-\dfrac{4}{111111}\right)\)

= \(10101\cdot\left(\dfrac{5}{111111}-\dfrac{4}{111111}+\dfrac{5}{222222}\right)\)

= \(10101\cdot\left(\dfrac{1}{111111}+\dfrac{5}{222222}\right)\)

= \(10101\cdot\left(\dfrac{2}{222222}+\dfrac{5}{222222}\right)\)

= \(10101\cdot\dfrac{7}{222222}\)

= \(\dfrac{10101\cdot7}{222222}=\dfrac{10101\cdot7}{10101\cdot22}=\dfrac{7}{22}\)

1 tháng 4 2017

10101.(\(\dfrac{5}{111111}+\dfrac{5}{222222}-\dfrac{4}{3.7.11.13.37}\))

= 10101.(\(\dfrac{5}{111111}+\dfrac{5}{222222}-\dfrac{4}{111111}\))

= 10101.(\(\dfrac{1}{111111}+\dfrac{5}{222222}\))

= 10101. \(\dfrac{7}{222222}\)

= \(\dfrac{10101.7}{222222}\)= \(\dfrac{70707}{22222}\)=\(\dfrac{7}{22}\)

Chúc pạn hok tốt!!!!!!!

20 tháng 1 2022

a. \(\dfrac{-6}{11}+\dfrac{5}{-11}< --1\)

b. \(\dfrac{-5}{16}+\dfrac{-3}{16}>-\dfrac{1}{3}\)

c. \(\dfrac{2}{5}>\dfrac{3}{4}+-\dfrac{1}{6}\)

d. \(\dfrac{5}{6}+\dfrac{-2}{3}>\dfrac{1}{12}+\dfrac{-4}{5}\)

4 tháng 5 2022

\(\dfrac{3}{2}x-0,2=\dfrac{3}{5}\)

\(\dfrac{3}{2}x-\dfrac{1}{5}=\dfrac{3}{5}\)

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

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

   \(x=\dfrac{4}{5}:\dfrac{3}{2}\)

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

   \(x=\dfrac{8}{15}\)

 

\(\dfrac{1}{3}+x=\dfrac{3}{4}\)

        \(x=\dfrac{3}{4}-\dfrac{1}{3}\)

        \(x=\dfrac{9}{12}-\dfrac{4}{12}\)

        \(x=\dfrac{5}{12}\)

 

\(1\dfrac{1}{2}x-\dfrac{2}{5}=\dfrac{1}{4}\)

\(\dfrac{3}{2}x-\dfrac{2}{5}=\dfrac{1}{4}\)

\(\dfrac{3}{2}x=\dfrac{1}{4}+\dfrac{2}{5}\)

\(\dfrac{3}{2}x=\dfrac{13}{20}\)

   \(x=\dfrac{13}{20}:\dfrac{3}{2}\)

   \(x=\dfrac{13}{20}\cdot\dfrac{2}{3}\)

   \(x=\dfrac{13}{30}\)

 

\(\dfrac{11}{8}-\dfrac{3}{8}\cdot x=\dfrac{1}{8}\)

          \(\dfrac{3}{8}\cdot x=\dfrac{11}{8}-\dfrac{1}{8}\)

          \(\dfrac{3}{8}\cdot x=\dfrac{5}{4}\)

                \(x=\dfrac{5}{4}:\dfrac{3}{8}\)   

                \(x=\dfrac{5}{4}\cdot\dfrac{8}{3}\)

                \(x=\dfrac{10}{3}\)