Trả lời:

71+65.4=x+140/x+260

x+140/x+260=71+65.4

x+140/x+260=71+260

x+140/x=71

x/x+140/x=71

1+140/x=71

140/x=71-1

140/x=70

x=140/70

x=2

vậy x=2

cậu ơi cái chỗ 71+65x4 là nhân 4 hay là 65 nhân x nhân 4 ạ

x = 2 nhé

71 + 65 x 4 = x + 140/x + 260

x + 140/x + 260 = 71 + 65 x 4

x + 140/x + 260 = 71 + 260

x + 140/x = 71

x/x + 140/x  = 71

1 + 140/x = 71

140/x = 71 - 1

140/x = 70

     x = 140/70

     x = 2

71 + 65 x 4 = x + 140/x + 260

x + 140/x + 260 = 71 + 65 x 4

x + 140/x + 260 = 71 + 260

x + 140/x = 71

x/x + 140/x  = 71

1 + 140/x = 71

140/x = 71 - 1

140/x = 70

     x = 140/70

     x = 2

71+ 65x4 = (x+140) :x + 260

71 + 260 = x:x + 140:x + 260

71 + 260 - 1- 260 = 140x

70 = 140x 

x= 70 : 140

x= 1/2

\(71+65\times4=\frac{x+140}{x}+260\)

                   \(71+260=\frac{x}{x}+\frac{140}{x}+260\)

                   \(71\)              \(=1+\frac{140}{x}\)

                   \(70\)              \(=\frac{140}{x}\)

                   \(x\)                \(=2\) 

\(\frac{x+140}{x+260}=71+65.4\)

\(\Leftrightarrow\frac{x+140}{x+260}=71+260\)

\(\Leftrightarrow\frac{x+140}{x+260}=331\)

\(\Leftrightarrow x+140=\left(x+260\right)331\)

\(\Leftrightarrow x+140=86060+331x\)

\(\Leftrightarrow x-331x=85920\)

\(\Leftrightarrow x\left(331-1\right)=85920\)

\(\Leftrightarrow x330=85920\)

\(\Leftrightarrow x\approx260,2\)

\(\frac{x+140}{x+260}=71+65\times4\)

\(\Rightarrow\frac{x+260-120}{x+260}=331\)

\(\Rightarrow1-\frac{120}{x+260}=331\)

\(\Rightarrow\frac{120}{x+260}=-330\)

\(\Rightarrow x+260=\frac{120}{-330}\)

\(\Rightarrow x+260=\frac{-4}{11}\)

\(\Rightarrow x=\frac{-4}{11}-260=-\frac{4}{11}-\frac{2860}{11}=\frac{-2864}{11}\)

\(\frac{x+140}{x+260}=71+65.4\)

<=> \(\frac{x+140}{x-260}=331\)

<=> \(\frac{x+140}{x-260}=\frac{331x-86060}{x-260}\)

,<=> \(x+140=331x-86060\)

<=> \(-330x=-86200\)

<=> \(x=\frac{8620}{33}\)