To find the equation that represents the sum of three consecutive even integers where the first integer is \( x \), the second integer is \( x + 2 \), and the third integer is \( x + 4 \), you can set up the equation as follows:
\[ x + (x + 2) + (x + 4) = 36 \]
This simplifies to:
\[ 3x + 6 = 36 \]
Thus, the correct equation that can be used to find the first integer is:
3x + 6 = 36