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13 tháng 9 2020

\(\frac{x+10}{30}+\frac{x+14}{43}+\frac{x+5}{95}+\frac{x+130}{5}=0\)

\(\Leftrightarrow\left(\frac{x+10}{30}+3\right)+\left(\frac{x+14}{43}+2\right)+\left(\frac{x+5}{95}+1\right)+\left(\frac{x+130}{5}-6\right)=0\)

\(\Leftrightarrow\frac{x+10+90}{30}+\frac{x+14+86}{43}+\frac{x+5+95}{95}+\frac{x+130-30}{5}=0\)

\(\Leftrightarrow\frac{x+100}{30}+\frac{x+100}{43}+\frac{x+100}{95}+\frac{x+100}{5}=0\)

\(\Leftrightarrow\left(x+100\right)\left(\frac{1}{30}+\frac{1}{43}+\frac{1}{95}+\frac{1}{5}\right)=0\)

Vì \(\frac{1}{30}+\frac{1}{43}+\frac{1}{95}+\frac{1}{5}\ne0\)

=> x + 100 = 0

=> x = -100

\(\left(\frac{x-10}{30}-3\right)+\left(\frac{x-14}{43}-2\right)+\left(\frac{x-5}{95}-1\right)+\left(\frac{x-148}{8}+6\right)=0\)

\(\Leftrightarrow\left(\frac{x-10}{30}-\frac{90}{30}\right)+\left(\frac{x-14}{43}-\frac{86}{43}\right)+\left(\frac{x-5}{95}-\frac{95}{95}\right)+\left(\frac{x-148}{8}+\frac{48}{8}\right)=0\)

\(\Leftrightarrow\frac{x-100}{30}+\frac{x-100}{43}+\frac{x-100}{95}+\frac{x-100}{8}=0\)

\(\Leftrightarrow\left(x-100\right).\left(\frac{1}{30}+\frac{1}{43}+\frac{1}{95}+\frac{1}{8}\right)=0\)

\(\Rightarrow x-100=0\)( Do \(\frac{1}{30}+\frac{1}{43}+\frac{1}{95}+\frac{1}{8}\ne0\)

=> x=100

30 tháng 6 2016

1. \(\Leftrightarrow\frac{59-x}{41}+1+\frac{57-x}{43}+1+\frac{55-x}{45}+1+\frac{51-x}{49}+1=-5+5\)

 \(\Leftrightarrow\frac{100-x}{41}+\frac{100-x}{43}+\frac{100-x}{45}+\frac{100-x}{47}+\frac{100-x}{49}=0\)

 \(\Leftrightarrow\left(100-x\right)\left(\frac{1}{41}+\frac{1}{43}+\frac{1}{45}+\frac{1}{47}+\frac{1}{49}\right)=0\)

 \(\Leftrightarrow x-100=0\Leftrightarrow x=100\)

2. \(\Leftrightarrow\frac{x-5}{1990}+1+\frac{x-15}{1980}+1+\frac{x-25}{1970}=\frac{x-1990}{5}+1+\frac{x-1980}{15}+1+\frac{x-1970}{25}+1\)

   \(\Leftrightarrow\frac{x-1995}{1990}+\frac{x-1995}{1980}+\frac{x-1995}{1970}=\frac{x-1995}{5}+\frac{x-1995}{15}+\frac{x-1995}{25}\)

   \(\Leftrightarrow\frac{x-1995}{1990}+\frac{x-1995}{1980}+\frac{x-1995}{1970}-\frac{x-1995}{5}-\frac{x-1995}{15}-\frac{x-1995}{25}=0\)

  \(\Leftrightarrow\left(x-1995\right)\left(\frac{1}{1990}+\frac{1}{1980}+\frac{1}{1970}-\frac{1}{5}-\frac{1}{15}-\frac{1}{25}\right)=0\)

  \(\Leftrightarrow x-1995=0\Leftrightarrow x=1995\)

30 tháng 6 2016

câu 3 hình như sai đề

23 tháng 2 2018

a, => (x-10/30 - 3) + (x-14/43 - 2) + (x-5/95 - 1) + x-100/8 = 0 ( vì x-148/8 = x-100/8 + 48/8 = x-100/8 + 6 )

=> x-100/30 + x-100/43 + x-100/95 + x-100/8 = 0

=> (x-100).(1/30 + 1/43 + 1/95 + 1/8) = 0

=> x-100 = 0 ( vì 1/30+1/43+1/95+1/8 > 0 )

=> x = 100

Vậy x = 100

Tk mk nha

27 tháng 2 2018

196345−x​+196840−x​+197335−x​+197830−x​=−4
\left(\frac{45-x}{1963}+1\right)+\left(\frac{40-x}{1968}+1\right)+\left(\frac{35-x}{1973}+1\right)+\left(\frac{30-x}{1978}+1\right)=0(196345−x​+1)+(196840−x​+1)+(197335−x​+1)+(197830−x​+1)=0
\frac{2008-x}{1963}+\frac{2008-x}{1968}+\frac{2008-x}{1973}+\frac{2008-x}{1978}=019632008−x​+19682008−x​+19732008−x​+19782008−x​=0
\left(2008-x\right)\left(\frac{1}{1963}+\frac{1}{1968}+\frac{1}{1973}+\frac{1}{1978}\right)=0(2008−x)(19631​+19681​+19731​+19781​)=0
=> 2008 - x = 0 ( vì 1/ 1963 + ... khác 0 )
=> x = 2008

Ta có : \(\frac{45-x}{1963}+\frac{40-x}{1968}+\frac{35-x}{1973}+\frac{30-x}{1978}+4=0\)

\(\Leftrightarrow\frac{45-x}{1963}+1+\frac{40-x}{1968}+1+\frac{35-x}{1973}+1+\frac{30-x}{1978}=0\)

\(\Leftrightarrow\frac{2008-x}{1963}+\frac{2008-x}{1968}+\frac{2008-x}{1973}+\frac{2008-x}{1978}=0\)

\(\Leftrightarrow\left(2008-x\right)\left(\frac{1}{1963}+\frac{1}{1968}+\frac{1}{1973}+\frac{1}{1978}\right)=0\)

Vì \(\left(\frac{1}{1963}+\frac{1}{1968}+\frac{1}{1973}+\frac{1}{1978}\right)\ne0\)

Nên : 2008 - x = 0 

<=> x = 2008

Vậy x = 2008

3 tháng 7 2017

a ) Ta có : \(\frac{x+11}{10}+\frac{x+21}{20}+\frac{x+31}{30}=\frac{x+41}{40}+\frac{x+101}{5}\) 

\(\Leftrightarrow\left(\frac{x+11}{10}-1\right)+\left(\frac{x+21}{10}-1\right)+\left(\frac{x+31}{30}-1\right)=\left(\frac{x+41}{40}-1\right)+\left(\frac{x+101}{50}-2\right)\)

\(\Leftrightarrow\frac{x+1}{10}+\frac{x+1}{20}+\frac{x+1}{30}=\frac{x+1}{40}+\frac{x+1}{50}\)

\(\Rightarrow\frac{x+1}{10}+\frac{x+1}{20}+\frac{x+1}{30}-\frac{x+1}{40}-\frac{x+1}{50}=0\)

\(\Leftrightarrow\left(x+1\right)\left(\frac{1}{10}+\frac{1}{20}+\frac{1}{30}-\frac{1}{40}-\frac{1}{50}\right)=0\)

Mà \(\left(\frac{1}{10}+\frac{1}{20}+\frac{1}{30}-\frac{1}{40}-\frac{1}{50}\right)\ne0\)

Nên x + 1 = 0

=> x = -1

3 tháng 7 2017

còn b vs c thì sao ạ