Question

[phan thi ngoc mai]

1.Tìm x biết :

x+(x+1)+(x+2)+...+(x+100)=10100

Answer 1

[Nguyễn Hoàng Minh]

\(\Rightarrow\dfrac{\left(x+100+x\right)\left(x+100-x+1\right)}{2}=10100\\ \Rightarrow101\left(2x+100\right)=20200\\ \Rightarrow2x+100=200\Rightarrow x=50\)

Answer 2

[Tử Nguyệt Hàn]

<=>     101x+(1+99)+(2+98)+....+(49+51)+100+50=10100
<=>      101x+5050=10100
<=>      101x=5050
<=>            x=50