3 + \(\frac{3}{20}\)+   \(\frac{3}{13}\) + \(\frac{3}{2013}\)

X x                                                                =  \(\frac{5}{3}\)

            5 + \(\frac{5}{20}\) +  \(\frac{5}{13}\) + \(\frac{5}{2013}\)

          3 x ( 1 +  \(\frac{1}{20}\) + \(\frac{1}{13}\) + \(\frac{1}{2013}\) )

X  x                                                                        =  \(\frac{5}{3}\)

          5 x ( 1 + \(\frac{1}{20}\) +\(\frac{1}{13}\) +  \(\frac{1}{2013}\) ) 

X  x  \(\frac{3}{5}\) =   \(\frac{5}{3}\) => X =  \(\frac{25}{9}\) vậy X = \(\frac{25}{9}\)

Ta có  : \(X.\frac{3+\frac{3}{20}+\frac{3}{13}+\frac{3}{2013}}{5+\frac{5}{20}+\frac{5}{13}+\frac{5}{2013}}=\frac{5}{3}\)

\(\Leftrightarrow X.\frac{3\left(1+\frac{1}{20}+\frac{1}{13}+\frac{1}{2013}\right)}{5\left(1+\frac{1}{20}+\frac{1}{13}+\frac{1}{2013}\right)}=\frac{5}{3}\)

\(\Leftrightarrow X.\frac{3}{5}=\frac{5}{3}\Rightarrow X=\frac{5}{3}:\frac{3}{5}=\frac{5}{3}.\frac{5}{3}=\frac{25}{9}\)

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

còn b vs c thì sao ạ

b) Sai đề à bạn đề \(\frac{x+2}{42}+\frac{x+4}{22}=\frac{x+5}{23}+\frac{x+3}{43}\)  hả đề này mk làm đc 

tong bang bao nhiu vay

ko có kết quả thì làm sao mà tính được

Trl:

Mong bạn sửa lại đề vì đề không có tổng 

#z

Vì các phân số đều có dạng  
 
 
 

=>phần này dễ rùi bn tự lm nhé tích trung tỉ ngoại tỉ

\(x\cdot\frac{3+\frac{3}{20}+\frac{3}{13}+\frac{3}{2013}}{5+\frac{5}{20}+\frac{5}{13}+\frac{5}{2013}}=\frac{5}{3}\)

\(x\cdot\frac{3\cdot\left(1+\frac{1}{20}+\frac{1}{13}+\frac{1}{2013}\right)}{5\cdot\left(1+\frac{1}{20}+\frac{1}{13}+\frac{1}{2013}\right)}=\frac{5}{3}\)

\(x\cdot\frac{3}{5}=\frac{5}{3}\)

\(x=\frac{5}{3}:\frac{3}{5}\)

\(x=\frac{25}{9}\)

\(x.\frac{3+\frac{3}{20}+\frac{3}{13}+\frac{3}{2013}}{5+\frac{5}{20}+\frac{5}{13}+\frac{5}{2013}}=\frac{5}{3}\)

\(x.\frac{3.\left(1+\frac{1}{20}+\frac{1}{13}+\frac{1}{2013}\right)}{5.\left(1+\frac{1}{20}+\frac{1}{13}+\frac{1}{2013}\right)}=\frac{5}{3}\)

\(x.\frac{3}{5}=\frac{5}{3}\)

\(x=\frac{5}{3}:\frac{3}{5}\)

\(x=\frac{25}{9}\)

bạn skt ntt làm đúng rồi đấy bạn ơi

\(x.\frac{\frac{3}{20}+\frac{3}{13}+\frac{3}{2013}}{\frac{5}{20}+\frac{5}{13}+\frac{5}{2013}}=\frac{5}{3}\)

\(\Rightarrow x.\frac{3\left(\frac{1}{20}+\frac{1}{13}+\frac{1}{2013}\right)}{5\left(\frac{1}{20}+\frac{1}{13}+\frac{1}{2013}\right)}=\frac{5}{3}\)

\(\Rightarrow x.\frac{3}{5}=\frac{5}{3}\)

\(\Rightarrow x=\frac{5}{3}:\frac{3}{5}=\frac{25}{9}\)

vậy \(x=\frac{25}{9}\)