=> (x+1+x+100) x 100 : 2 = 5550
=> (2x+101) x 100 = 5550 x 2 = 11100
=> 2x+101 = 11100 + 100 = 111
=> 2x = 111-101 = 10
=> x = 10 : 2 = 5
k mk nha
(x+1)+(x+2)+(x+3)+...+(x+100)=5550
=> (x+x+x+...+x)+...+(1+2+3+...+100)=5550
=> 100x+5050=5550
100x=5550-5050
100x=500
x=500:100
x=5