Phá ngoặc
x + 1 + x + 2+ .... + x + 100 = 5750
100x + 100.101:2 = 5750
100x + 5050 = 5750
100x = 5750 - 5050 = 700
x = 700 : 100 = 7
=> x + 1 + x + 2 + ... + x + 100 = 5750
=> 100x + (1+2+...+100) = 5750
=> 100x + \(\frac{\left(100+1\right).100}{2}\) = 5750
=> 100x +5050 = 5750
=> 100x = 5750 - 5050
=> 100x = 700
=> x = 7
( x + x + ... + x ) + ( 1 + 2 + ... + 100 ) = 5750
100.x + 5050 = 5750
100.x = 700
x = 700 : 100
x = 7
tick nha
(x+x+x+....+x)+(1+2+3+...+100)=5750
100.x+5050+5750
100.x=5750-5050
100.x=700
x=700:10
x=7
vay x =7
(x+x+..+x)+(1+2+...+100)=5750
x.100+5050+5750
x.100=5750-5050=700
x=700:100
x=7
x+1x+2x+3+...+x+100=5750
x*{1+2+3+...+100}=5750
x*{100-1:1+1}=5750
x*100=5750
x=5750:100
x=57,5
