(x + 1) + (x + 2) + (x + 3) + ... + (x + 100) = 205550 ( có 100 cặp () )
<=> x+1+x+2+x+3+...+x+100=205550
<=> 100x + (1+2+3+...+100)= 205550
<=> 100x + (1+100).100/2=205550
<=>100x +101.50=205550
<=> 100x + 5050=205550
<=> 100x=200500
<=> x=2005
Vậy x=2005

( x + 1 ) + ( x + 2) + ( x + 3 ) + ... + ( x+ 100 ) = 205550
<=> ( x + x + x + ... + x ) + ( 1 + 2+ 3 + ... + 100 ) = 205550
<=> 100x + 5050 = 205550
<=> 100x = 200500
<=> x = 2005

biết: (x + 1) + (x + 2) + (x + 3) + ... + (x + 100) = 205550
<=>100.x+(1+2...+99+100)=205550
100x+[100.101/2]=205550
100x=205550-50.101=155050
x=1550,5

(x+1)+(x+2)+......+(x+100)=205550
<=> (x+x+...+x) + (1+2+3+...+100) = 205550
100 số hạng x 100 số hạng
<=> 100x + [100.(100+1) : 2] = 205550
<=> 100x + 5050 = 205550
<=> 100x = 200500
<=> x= 2005
Vậy x=2005

(x + 1) + (x + 2) + (x + 3) + ... + (x + 100) = 205550
(100x) + (1 + 2 + 3 +...........+ 100)=205550
(100x) + (101 x 50)=205550
(100x) + 5050 =205550
100x =205550 -5050
100x =200500
x=200500 : 100
X = 2005