\(x+2x+3x+...100x=5250\)
\(\Rightarrow x.\left(1+2+3+...100\right)=5250\)
\(\Rightarrow x.\left(100-1+1\right)\left(1+100\right):2=5250\)
\(\Rightarrow\dfrac{100.101}{2}=5250\Rightarrow50.101.x=5250\)
\(\Rightarrow x=\dfrac{5250}{50.101}=\dfrac{105}{101}\)
Đề bài bn tự viết lại nhé!
\(\Leftrightarrow x\left(\dfrac{100-1}{1}+1\right)=5250\)
\(\Leftrightarrow x100=5250\)
\(\Leftrightarrow x=5250:100\)
\(\Leftrightarrow x=52,5\)
Vậy x=52,5