Tìm x biết:
|x-2012|+|x-2013|=2014
tìm x biết (x+2014)/2011 + (x+2013)/2012 = (x+2012)/2013 + (x+2011)/2014
Tìm x biết (2012/1+2011/2+...+1/2012)/(1/2+1/3+...+1/2013):x=-2013/2014
Tìm số nguyên x, biết rằng 2014 = 2014 + 2013 + 2012 + ⋯ + x.
Tìm x biết : x + y/ 2012 = x. y /2013 = x - y /2014 .
x-y/2014=x+y/2012=x-y+x+y/2014+2012=2x/2026=x/1013 (theo tc dãy tỉ số bằng nhau)
ta lại có: x+y/2012=x.y/2013=x/2013 (chứng minh trên) => y=1
x-y/2014=x.y/2013=x/2013 => x-1/2014=x/2013
thì (x-1).2013=2014x
2013x-2013=2014x
-1x=2013 thì x=-2013
Tìm x biết a |3-2x|=x+1
b (1/2+1/3+...+1/2014)×x=2013/1+2012/2+...+2/2012+1/2013
Tìm x, biết: (x+4)/2012+(x+3)/2013=(x+2)/2014+(x+1)/2015
\(\frac{x+4}{2012}+\frac{x+3}{2013}=\frac{x+2}{2014}+\frac{x+1}{2015}\)
=> \(\frac{x+4}{2012}+1+\frac{x+3}{2013}+1=\frac{x+2}{2014}+1+\frac{x+1}{2015}+1\)
=> \(\frac{x+2016}{2012}+\frac{x+2016}{2013}=\frac{x+2016}{2014}+\frac{x+2016}{2015}\)
=> \(\frac{x+2016}{2012}+\frac{x+2016}{2013}-\frac{x+2016}{2014}-\frac{x+2016}{2015}=0\)
=> \(\left(x+2016\right).\left(\frac{1}{2012}+\frac{1}{2013}-\frac{1}{2014}-\frac{1}{2015}\right)=0\)
Vì \(\frac{1}{2012}>\frac{1}{2014};\frac{1}{2013}>\frac{1}{2015}\)
=> \(\frac{1}{2012}+\frac{1}{2013}-\frac{1}{2014}-\frac{1}{2015}\ne0\)
=> \(x+2016=0\)
=> \(x=-2016\)
Tìm x biết: x+1/2015+x+2/2014=x+3/2013+x+4/2012
tìm x biết (1/2 + 1/3 + 1/4 + .... + 1/2014 ) . x = 2013/1 + 2012/2 + ...+ 1/2013
Tìm x biết:
|x-2012|+|x-2013|=2014
Xét x < 2012 ta có :
2012 - x + 2013 - x = 2014 <=> 4025 - 2x = 2014 <=> 2x = 2011 => x = 1005,5
Xét 2012 ≤ x < 2013 ta có : x - 2012 + 2013 - x = 2014 <=> 1 = 2014 ( loại )
Xét x ≥ 2013 ta có :
x - 2012 + x - 2013 = 2014 <=> 2x - 4025 = 2014 <=> 2x = 6039 => x = 3019,5
Vậy x = { 1005,5 ; 3019,5 }
Tìm x biết: x-1/2015 + x/2014 + 1/503 = x-3/2013 + x/2012 + 1/1007