Tìm x: (x + 1) + (x + 3) + (x + 5) +...+ (x + 99) = 0

(x+1) + (x+3) + (x +5) +....+(x+99) = 0
(1/1.2 + 1/2.3 + 1/3.4 +....+1/8.9).x = 23/45
(2/11.13+2/13.15+...+2/19.21)-x + 221/231 = 4/3
giúp với.