x la 134

ai ghé qua đây hoặc online thì tick cho mk đc ko zậy

2678:[462-2(x-6)]=13

=> x=134

Tick mk vài cái cho lên 230 nha !!!

trên olm này, nếu ai đang đọc thì bố thí cho tớ. ai cũng tham tiền và điểm hỏi đáp. ai tick thì thank you tam giác

`(2/(11.13)+2/(13.15)+....+2/(19.21)).462-[0,04/(x+1,05):0,12=19`

`=>(1/11-1/13+1/13-1/15+....+1/19-1/21).462-(2/(50(x+1,05)).25/3=19`

`=>(1/11-1/21).462-1/(3(x+1,05))=19`

`=>10/231. 462-1/(3x+3,15)=19`

`=>20-1/(3x+3,15)=19

`=>1/(3x+3,15)=1`

`=>3x+3,15=1`

`=>3x=-2,15`

`=>x=-43/60`

Vậy `x=-43/60`

Giải: 

\(\left(\dfrac{2}{11.13}+\dfrac{2}{13.15}+...+\dfrac{2}{19.21}\right).462-\left[\dfrac{0,04}{x+1,05}:0,12\right]=19\) 

\(\left(\dfrac{1}{11}-\dfrac{1}{13}+\dfrac{1}{13}-\dfrac{1}{15}+...+\dfrac{1}{19}-\dfrac{1}{21}\right).462-\left[\dfrac{1}{\dfrac{25}{x+\dfrac{21}{20}}}:\dfrac{3}{25}\right]=19\) 

\(\left(\dfrac{1}{11}-\dfrac{1}{21}\right).462-\left[\dfrac{1}{25.\left(x+\dfrac{21}{20}\right)}:\dfrac{3}{25}\right]=19\) 

                             \(20-\left[\dfrac{25.1}{3.25.\left(x+\dfrac{21}{20}\right)}\right]=19\) 

                                              \(\dfrac{1}{3.\left(x+\dfrac{21}{20}\right)}=20-19\) 

                                               \(\dfrac{1}{3.x+\dfrac{63}{20}}=1\) 

                                      \(1:\left(3.x+\dfrac{63}{20}\right)=1\) 

                                                \(3.x+\dfrac{63}{20}=1:1\) 

                                                \(3.x+\dfrac{63}{20}=1\) 

                                                         \(3.x=1-\dfrac{63}{20}\) 

                                                         \(3.x=\dfrac{-43}{20}\) 

                                                            \(x=\dfrac{-43}{20}:3\) 

                                                            \(x=\dfrac{-43}{60}\)

chiu thoi

\(\left(\frac{2}{11\times13}+\frac{2}{13\times15}+\frac{2}{15\times17}+\frac{2}{17\times19}+\frac{2}{19\times21}\right)\times462-x=19\)

\(\left(\frac{1}{11}-\frac{1}{13}+\frac{1}{13}-\frac{1}{15}+...+\frac{1}{19}-\frac{1}{21}\right)\times462-x=19\)

\(\left(\frac{1}{11}-\frac{1}{21}\right)\times462-x=19\)

\(\frac{10}{231}\times462-x=19\)

\(20-x=19\)

\(\Rightarrow x=20-19=1\)

chịu thôi làm sao được chết mất

a)x-1,44:1,2=5,9

   x-1,44=5,9x1,2

  x-1,44=7,08

         x=7,08+1,44

           x=8,52

b)86,5-x:8,6=23,7

           x:8,6=86,5-23,7

           x:8,6=62,8

                x=62,8x8,6

                x=540,08

chúc bạn học tốt !!!

Ta có : \(\left(\frac{2}{11.13}+\frac{2}{13.15}+...+\frac{2}{19.21}\right)642-\left[0,04:\left(x+1,05\right)\right]:0,12=19\)

=> \(\left(\frac{1}{11}-\frac{1}{13}+\frac{1}{13}-\frac{1}{15}+...+\frac{1}{19}-\frac{1}{21}\right)642-0,04:\left(x+1,05\right):0,12=19\)

=> 

(nãy bấm nhầm) tiếp nà :

=> \(\left(\frac{1}{11}-\frac{1}{21}\right)462-0,04:\left(x+1,05\right):0,12=19\)

=> \(\frac{10}{231}.462-0,04:\left(x+1,05\right):0,12=19\)

=> \(20-0,04:\left(x+1,05\right):0,12=19\)

=> 0,04 : (x + 1,05) : 0,12 = 1

=> 0,04 : (x + 1,05) = 0,12

=> \(x+1,05=\frac{1}{3}\) 

=> \(x=\frac{1}{3}-1,05=...\)

\(\left(\frac{2}{11.13}+\frac{2}{13.15}+...+\frac{2}{19.21}\right)562-\left[0,04:\left(x+1,05\right)\right]:0,12=19\)

\(\Rightarrow2.\frac{1}{2}\left(\frac{1}{11}-\frac{1}{13}+\frac{1}{13}-\frac{1}{15}+...+\frac{1}{19}-\frac{1}{21}\right)462-\left[0,04:\left(x+1,05\right)\right]:0,12=19\)

\(\Rightarrow\left(\frac{1}{11}-\frac{1}{21}\right)462-\left[0,04:\left(x+1,05\right)\right]:0,12=19\)

\(\Rightarrow\frac{10}{231}.462-\left[0,04:\left(x+1,05\right)\right]:0,12=19\)

\(\Rightarrow20-\left[0,04:\left(x+1,05\right)\right]0,12=19\)

\(\Rightarrow\left[0,04:\left(x+1,05\right)\right]:0,12=20-19=1\)

\(\Rightarrow0,04:\left(x+1,05\right)=1.0,12=0,12\)

\(\Rightarrow x+1,05=0,04:0,12=\frac{1}{3}\)

\(\Rightarrow x=\frac{1}{3}-1,05=\frac{1}{3}-\frac{105}{100}=-\frac{43}{60}\)

(Làm vậy đúng không?)