We start with the equation given for the sum of three consecutive even integers:
\[ x + (x + 2) + (x + 4) = 120 \]
Now, we simplify the left side of the equation:
\[ x + x + 2 + x + 4 = 120 \]
Combining like terms:
\[ 3x + 6 = 120 \]
Next, we isolate \(3x\) by subtracting 6 from both sides:
\[ 3x = 120 - 6 \]
\[ 3x = 114 \]
Now, we divide both sides by 3 to solve for \(x\):
\[ x = \frac{114}{3} \]
\[ x = 38 \]
Now that we have the value of \(x\), we can find the three consecutive even integers:
- First integer: \(x = 38\)
- Second integer: \(x + 2 = 38 + 2 = 40\)
- Third integer: \(x + 4 = 38 + 4 = 42\)
The largest of the three integers is:
\[ \boxed{42} \]