Find three consecutive odd integers with a sum of -51 answer

Hello : 
let three consecutive odd integers : (2n+1) , (2n+3) ,(2n+5)
 (2n+1)+ (2n+3)+(2n+5) = 51
6n + 9 = 51
6n = 45
n = 42/6
n = 7
if n = 7 : 2(7)+1 = 15
             : 2(7) +3 =17
             : 2(7) +5 = 19
three consecutive odd integers with a sum of 51 are:  15 , 17 , 19
15+17+19 =

Wait i don’t get it can you explain more?:)!