Theo đề ta có:
(x+1)+(x+2)+...+(x+100)=x+1+x+2+x+3+x+4+....+x+100
=[(100-1):(2-1)+1]x + (1+2+3+....+100)
=100x + [(100-1):(2-1)+1](100+1):2
=100x + 5050 = 5750
=> 100x = 5750-5050=700
=> x = 700:100
=> x=7
Selfie chào buổi tối nè,chào mn.
(x+1)+(x+2)+...+(x+100)=5750
100x+(1+2+3+...+100)=5750
100x+5050=5750
100x=5750-5050
100x=200
x=200:100
x=2
Vậy: x=2