`#Kenshiro`
`x (x+1)+(x+3)+(x+5)+......+(x+99)=0`
`⇒(x + 1) + (x + 3) + .... + (x + 99) = 0`
`=> (x + 1 + x + 99) + .... + (x + 49 + x + 51) = 0`
`=> (x + 100) + (x + 100) + .... (x + 100) = 0`
`=> (2x + 100). 50/2 = 0`
`=> 2x + 100 = 0`
`=> 2x = -100`
`⇒ x = -100 : 2`
`=> x = -50`