Question

Tìm x biết : \(2x+3x+4x+...+2014x=2015\cdot2016\)

Answer 1

4030/1007 , 100%

Answer 2

x(2+3+4+...+2014)=2015.2016

Đặt A=2+3+4+...+2014

=>A=[(2014+2).2012)/2

A=(2016.2012)/2

A=2016.1006

Thay A vào biểu thức:

x.2016.1006=2015.2016

x.1006=2015

x=2015/1006

Answer 3

Ta có :

       \(2x+3x+4x+...+2014x=2015.2016\)

\(\Rightarrow\left(2+3+4+...+2014\right)x=2015.2016\)

\(\Rightarrow\frac{2013.2016}{2}x=2015.2016\)

\(\Rightarrow2013.1008x=2015.1008.2\)

\(\Rightarrow2013x=2015.2\)

\(\Rightarrow x=\frac{2015.2}{2013}=\frac{4030}{2013}\)

Answer 4

2x+3x+4x+...+2014x=2015.2016

x(2+3+4+...+2014)=2015.2016

2029104x=2015.2016

x=2015.2016:2029104

x=4030/2013