What are 3 consecutive integers who's sum is 396?

Since it's three consecutive integers, the equation will end up like this:

x+x+1+x+2 = 396.
Combine like terms. All the x's will add together to become 3x, while the ones without will be 1+2 = 3.
3x+3 = 396.
We need to start getting the x by itself. We must subtract 3 from both sides. This is how it should end up:
3x = 393.
Then, we will finally get x by itself by dividing 3 by both sides. 
x = 131. The answer is x = 131.

Hope i can you!