Explanation

We know that the difference of their squares is 84, so we can write the equation:

(x+2)^2 - x^2 = 84

Expanding the equation, we get:

x^2 + 4x + 4 - x^2 = 84

Simplifying the equation, we get:

4x + 4 = 84

Subtracting 4 from both sides, we get:

4x = 80

Dividing both sides by 4, we get:

x = 20

So, the two consecutive even numbers are 20 and 22.

The sum of these numbers is:

20 + 22 = 42