x . 500+ (1+3+5+....+999)=0
x.500+ 250000=0
x. 500= 0-250000
x . 500 = -250000
x = -250000: 500
x= -500
\(x\in\left\{-1;-3;-5;-7;...;-997;-999\right\}\)
[(x+1)+(x+999)]+[(x+3)+(x+997)+...+[(x+499)+(x+501)]=0
(x.2+1+999).225=0
x.2+1000=0:225=0
x.2=0-1000=-1000
x=-1000:2=-500
tích mình tròn 60 với !