=> x.2013+[(1+2013).2013:2]=0

=> x.2013+(2014.2013:2)=0

=> x.2013+2027091=0

=> x.2013=0-2027091

=> x.2013=(-2027091)

=> x=(-2027091):2013

=> x=(-1007)

(x+1)+(x+2)+(x+3)+...(x+2013) = (x nhân 2013 ) + (1+2+...+2013)

x=1007

Tick mk vài cái lên 280 nha !!!

=>(x-1)/2015 - 1 + (x-2(/2014 -1 = (x-3)/2013 -1 + (x-4)/2012 -1

=>(x-2016)*(1/2015+1/2014-1/2013-1/2012)=0

=>x=2016

Trừ 1 ở mỗi p/s,ta có:

\(\left(\frac{x-1}{2015}-1\right)+\left(\frac{x-2}{2014}-1\right)=\left(\frac{x-3}{2013}-1\right)+\left(\frac{x-4}{2012}-1\right)\)

\(\Leftrightarrow\left(\frac{x-2016}{2015}\right)+\left(\frac{x-2016}{2014}\right)=\left(\frac{x-2016}{2013}\right)+\left(\frac{x-2016}{2012}\right)\)

\(\Leftrightarrow\frac{x-2016}{2015}+\frac{x-2016}{2014}-\frac{x-2016}{2013}-\frac{x-2016}{2012}=0\)

\(\Leftrightarrow\left(x-2016\right)\left(\frac{1}{2015}+\frac{1}{2014}-\frac{1}{2013}-\frac{1}{2012}\right)=0\)

Vì \(\frac{1}{2015}+\frac{1}{2014}-\frac{1}{2013}-\frac{1}{2012}\ne0\)

=>x-2016=0

=>x=2016

Vậy..................

mình hỏi bài này :tìm số tự nhiên x biết :(x-2)^2014=(x-2)^2016

lạy ông đi qua lạy bà đi lại! cho con mấy cái tick! cả ngày nay con chưa được tick gì hết

\(\frac{2}{6}+\frac{2}{12}+...+\frac{2}{x.\left(x+1\right)}=\frac{2011}{2013}\)

\(\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{x}-\frac{1}{x+1}=\frac{2011}{2013}:2\)

\(\frac{1}{2}-\frac{1}{x+1}=\frac{2011}{4026}\)

\(\frac{\left(x+1-2\right)}{2.\left(x+1\right)}=\frac{2011}{4026}\)