Let x be the EVEN number half way between the two unknown consecutive odd numbers.
Then your equation is
+ = 650
x^2 - 2x + 1 + x^2 + 2x + 1 = 650
2x^2 + 2 = 650
2x^2 = 650-2 = 648
x^2 = 648/2 = 324
x = = +/- 18.
So, for x we have two values 18 and - 18.
They give two pairs of solutions to the problem: (17,19) and (-19,-17). ANSWER