It is -21.
If x is an odd integer, then the next odd integer would be x + 2. (an example: 5 is an odd integer. The next odd integer is 5+2, or 7).
Based on this, we can make this equation and solve for x to find the answer:
x + (x + 2) + (x + 4) = -57
x is the smallest integer, x+2 is the next odd integer, and x+4 is the third odd integer.
Now we can solve
Combining like terms
3x + 6 = -57
3x = -63
x = -21
