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\(\dfrac{x+29}{19}+\dfrac{x+14}{36}+\dfrac{x+26}{15}=\left(-7\dfrac{2}{11}\right)+\left(-1\dfrac{9}{11}\right)\)

=>\(\dfrac{x+29}{19}+\dfrac{x+14}{36}+\dfrac{x+26}{15}=-7-\dfrac{2}{11}-1-\dfrac{9}{11}\)

=>\(\dfrac{x+29}{19}+\dfrac{x+14}{36}+\dfrac{x+26}{15}=-9\)

=>\(\left(\dfrac{x+29}{19}+3\right)+\left(\dfrac{x+14}{36}+2\right)+\left(\dfrac{x+26}{15}+4\right)=0\)

=>\(\dfrac{x+86}{19}+\dfrac{x+86}{36}+\dfrac{x+86}{15}=0\)

=>\(\left(x+86\right)\left(\dfrac{1}{19}+\dfrac{1}{36}+\dfrac{1}{15}\right)=0\)

=>x+86=0

=>x=-86

28 tháng 2 2018

bằng 2

29 tháng 3 2019

đáp án đúng = 2

4 tháng 2 2017

Phương trình 1:
\(\frac{x-85}{15}+\frac{x-74}{13}+\frac{x-67}{11}+\frac{x-64}{9}=10\)
\(\Rightarrow\frac{x-85}{15}+\frac{x-74}{13}+\frac{x-67}{11}+\frac{x-64}{9}-10=0\)
\(\Rightarrow\left(\frac{x-85}{15}-1\right)+\left(\frac{x-74}{13}-2\right)+\left(\frac{x-67}{11}-3\right)+\left(\frac{x-64}{9}-4\right)=0\)
\(\Rightarrow\frac{x-85-15}{15}+\frac{x-74-26}{13}+\frac{x-67-33}{11}+\frac{x-64-36}{9}=0\)
\(\Rightarrow\frac{x-100}{15}+\frac{x-100}{13}+\frac{x-100}{11}+\frac{x-100}{9}=0\)
\(\Rightarrow\left(x-100\right)\left(\frac{1}{15}+\frac{1}{13}+\frac{1}{11}+\frac{1}{9}\right)=0\)
Do \(\frac{1}{15}+\frac{1}{13}+\frac{1}{11}+\frac{1}{9}\ne0\)
\(\Rightarrow x-100=0\)
\(\Rightarrow x=100\)
Vậy x = 100.

4 tháng 2 2017

Phương trình 3:
\(\frac{1909-x}{91}+\frac{1907-x}{93}+\frac{1905-x}{95}+\frac{1903-x}{97}+4=0\)
\(\Rightarrow\left(\frac{1909-x}{91}+1\right)+\left(\frac{1907-x}{93}+1\right)+\left(\frac{1905-x}{95}+1\right)+\left(\frac{1903-x}{97}+1\right)=0\)
\(\Rightarrow\frac{1909-x+91}{91}+\frac{1907-x+93}{93}+\frac{1905-x+95}{95}+\frac{1903-x+97}{97}=0\)
\(\Rightarrow\frac{2000-x}{91}+\frac{2000-x}{93}+\frac{2000-x}{95}+\frac{2000-x}{97}=0\)
\(\Rightarrow\left(2000-x\right)\left(\frac{1}{91}+\frac{1}{93}+\frac{1}{95}+\frac{1}{97}\right)=0\)
Do \(\frac{1}{91}+\frac{1}{93}+\frac{1}{95}+\frac{1}{97}\ne0\)
\(\Rightarrow2000-x=0\)
\(\Rightarrow x=2000\)
Vậy x = 2000.

2 tháng 8 2017

 mik ko chép lại đề, mik làm luôn: 

a)  x - \(\frac{31}{36}=\frac{-13}{38}\)

x = \(\frac{-13}{18}+\frac{31}{36}\)

\(x=\frac{5}{36}\)

b)\(2-x-\frac{3}{7}=\frac{9}{-21}\)

\(\frac{11}{7}-x=\frac{3}{7}\)

x = \(\frac{11}{7}-\frac{3}{7}\)

x = 8/7

c) x + 3/11 = 23/44

x = 23/44 - 3/11

x = 1/4

d) \(\frac{1}{12}-x=\frac{-11}{9}\)

x = \(\frac{1}{12}+\frac{11}{9}\)

x = 47/36

e) \(x-\frac{2}{3}=\frac{-17}{3}\)

x= -17/3 + 2/3

x = -5 

f) \(x-\frac{1}{2}=\frac{11}{4}.\frac{3}{11}\)

x - 1/2 = 3/4

x = 3/4 + 1/2 

x = 5/4

g) \(2x+\frac{3}{8}=\frac{-21}{32}.\frac{4}{7}\)

2x + 3/8 = -3 / 8

2x = -3/8 - 3/8 

2x = -9/8

x = -9/8.1/2 

x = -9/16

h) x - \(\frac{x}{3}=\frac{3}{57}.\frac{19}{12}\)

x  - \(\frac{x}{3}=\frac{1}{12}\)

x = \(\frac{1}{12}+\frac{x}{3}\)

x = \(\frac{1+4x}{12}\)

=> 12x = 1+4x

12x - 4x = 1

8x = 1

x = 1/8 

2 tháng 8 2017

Trả lời nhanh gọn lẹ nhé, mình k cho :)

23 tháng 6 2020

Bài 1:

a) \(\frac{25}{4}+\frac{-5}{4}=\frac{25-5}{4}=\frac{20}{4}=5\)

b)\(\frac{-5}{9}+\left(\frac{-2}{7}\right)=\frac{-35}{63}+\left(\frac{-18}{63}\right)=\frac{-53}{63}\)

c) \(\frac{1}{4}+\frac{9}{11}+\frac{7}{4}+\left(\frac{-2}{11}\right)=\left(\frac{1}{4}+\frac{7}{4}\right)+\left(\frac{-2}{11}+\frac{9}{11}\right)=2+\frac{7}{11}=\frac{22+7}{11}=\frac{29}{11}\)

d) \(\frac{-5}{19}.\frac{8}{19}+\left(\frac{-14}{19}\right).\frac{11}{19}=\frac{-40}{361}-\frac{151}{361}=-\frac{191}{361}\)

23 tháng 6 2020

Bài 2: 

a) \(x+\frac{5}{9}=\frac{-8}{9}\)  \(\Leftrightarrow x=\frac{-8}{9}-\frac{5}{9}\)  \(\Leftrightarrow x=-\frac{13}{9}\)

b) \(\frac{-1}{8}-x=\frac{9}{20}\)  \(\Leftrightarrow x=\frac{-1}{8}-\frac{9}{20}\)  \(\Leftrightarrow x=\frac{-5}{40}-\frac{18}{40}\)  \(\Leftrightarrow x=-\frac{23}{40}\)

c) (x + 5)3 - 12 = 15

\(\Leftrightarrow\)(x + 5)3 = 27

\(\Leftrightarrow\)x + 5 = 3

\(\Leftrightarrow\)x = -2

d) \(\left|x-3\right|-\frac{4}{15}=\frac{26}{15}\)  \(\Leftrightarrow\left|x-3\right|=2\)  \(\Leftrightarrow\orbr{\begin{cases}x-3=2\\x-3=-2\end{cases}}\)  \(\Leftrightarrow\orbr{\begin{cases}x=5\\x=1\end{cases}}\)

15 tháng 3 2019

\(a)\frac{1}{3}+\frac{-2}{5}+\frac{1}{6}+\frac{-1}{5}\le x< \frac{-3}{4}+\frac{2}{7}+\frac{-1}{4}+\frac{3}{5}+\frac{5}{7}\)

\(\Rightarrow\frac{1}{3}+\frac{1}{6}+\frac{-2}{5}+\frac{-1}{5}\le x< \frac{-3}{4}+\frac{-1}{4}+\frac{2}{7}+\frac{5}{7}+\frac{3}{5}\)

\(\Rightarrow\frac{2}{6}+\frac{1}{6}+\frac{-3}{5}\le x< -1+1+\frac{3}{5}\)

\(\Rightarrow\frac{1}{2}+\frac{-3}{5}\le x< \frac{3}{5}\)

\(\Rightarrow\frac{-1}{10}\le x< \frac{6}{10}\)

\(\Rightarrow-1\le x< 6\)

\(\Rightarrow x\in\left\{-1;0;1;2;3;4;5\right\}\)

Bài b tương tự

17 tháng 3 2019

bạn ơi bạn giải câu b được ko. mk ko biết làm câu b

9 tháng 2 2019

â, -4/9(7/15+8/15)=-4/9

b,-5/4(16/25+9/25)=-5/4

,..... 

dài quá mik làm ko hết 

hok tốt

14 tháng 8 2016

\(S=\frac{\left(9\frac{3}{8}:5,2+3,4.2\frac{7}{34}\right):1\frac{9}{16}}{0,31.8\frac{2}{2}-5,61:27\frac{1}{3}}\)\(\Rightarrow S=\frac{\left(\frac{75}{8}.\frac{5}{26}+\frac{17}{5}.\frac{75}{34}\right):\frac{25}{16}}{\frac{31}{100}.9-\frac{561}{100}.\frac{3}{82}}\)\(\Rightarrow S=\frac{\left(\frac{75.5}{8.26}-\frac{17.75}{5.34}\right).\frac{16}{25}}{\frac{31.9}{100}-\frac{561.3}{100.82}}\)

\(\Rightarrow S=\frac{\left(\frac{375}{208}-\frac{15}{2}\right).\frac{16}{25}}{\frac{279}{100}-\frac{1682}{8200}}\)\(\Rightarrow S=\frac{\frac{-1185}{208}.\frac{16}{25}}{\frac{21196}{8200}}\)\(\Rightarrow S=\frac{-237}{65}:\frac{21196}{8200}\)\(\Rightarrow S=\frac{-194340}{137774}\)

\(\Rightarrow x=\frac{2}{3}S\Rightarrow x=\frac{2}{3}.\frac{-194340}{137774}\Rightarrow x=\frac{-388680}{413322}\)

14 tháng 8 2016

\(M=\frac{23\frac{11}{15}-26\frac{13}{20}}{12^2+5^2}:\frac{1-\frac{1}{3}-\frac{1}{42}-\frac{1}{56}}{3^2.13.2}-\frac{19}{37}\)\(\Rightarrow M=\frac{\frac{356}{15}-\frac{533}{20}}{12^2+5^2}:\frac{\frac{5}{8}}{3^2.13.2}-\frac{19}{37}\)

\(\Rightarrow M=\frac{\frac{-35}{12}}{12^2+5^2}.\frac{3^2.13.2}{\frac{5}{8}}-\frac{19}{37}\)\(\Rightarrow M=\frac{-84}{13}-\frac{19}{37}\Rightarrow M=\frac{-3355}{481}\Rightarrow15\%M=\frac{-3355}{481}.15\%\Rightarrow15\%M=\frac{-2013}{1924}\)