Question

Tìm c nguyên biết: x + ( x +1) +  (x+2) + ....+ (x + 2019 ) + 2019 = 2019

o l m . v n

Answer 1

Ta có: \(x+\left(x+1\right)+\left(x+2\right)+...+\left(x+2019\right)+2019=2019\)

   \(\Leftrightarrow\left(x+x+x+...+x\right)+\left(0+1+2+...+2019\right)=0\)( có 2020 chữ x )

   \(\Leftrightarrow2020x+2039190=0\)

   \(\Leftrightarrow x=-1009,5\)

Answer 2

Ta có : \(x+\left(x+1\right)+\left(x+2\right)+...+\left(x+2019\right)+2019=2019\)

\(\Rightarrow x+x+1+x+2+...+x+2019=0\)

\(\Rightarrow2020x+\left(1+2+3+...+2019\right)=0\)

\(\Rightarrow2020x+\frac{2019.2020}{2}=0\)

\(\Rightarrow2020x+2039190=0\)

\(\Rightarrow2020x=-2039190\)

\(\Rightarrow x=1009,5\)

Vậy \(x=1009,5\)