Question

 ( x +1 ) + ( x + 2 ) + ( x + 3 ) ....................... ( x + 100 ) = 5750

tìm x 

Answer 1

(x+1)+(x+2)+.......+(x+100) = 5750

=> 100x + (1+2+3+4+....+100) = 5750

=> 100x + 100.(100 + 1).2 = 5750

=> 100x + 5050 = 5750

=> 100x = 5750 - 5050 = 700

Vậy x = 700 : 100 = 7

Answer 2

(x+1)+(x+2)+(x+3)+...+(x+100)=5750 
x + 1 + x + 2 + x + 3 + .... + x + 100 = 5750 
(x + x + x + ... + x) + (1 + 2 + 3 + ... + 100) = 5750 
100x + 5050 = 5750 
100x = 5750 - 5050 = 700 
x = 700 : 100 = 7