We can divide 84 by 2 and add and subtract 1 from the result to get 41 and 43 as the two numbers. For any number n that is divisible by 2, we can solve this problem by finding n/2 + 1 and n/2-1. These will always be consecutive odd numbers and if you add them up, you get n.
If n is the smallest integer, the other integer must be two more than that, because it has to be odd. The two numbers add up to 84, so the other side of the equation is 84.