\(\left(x+1\right)+\left(x+2\right)+\left(x+3\right)+....+\left(x+100\right)=5070.\)
\(\left(x+x+x+x+....+x\right)+\left(1+2+3+....+100\right)=5070\)
\(100x+101.100:2=5070\)
\(100x+5050=5070\)
\(100x=5070-5050=20\)
\(x=20:100=\frac{20}{100}=\frac{2}{10}=\frac{1}{5}=0,2\)