shankar.ashwin's solution is perfect.

That said, I'd like to mention that, with some consecutive odd integer questions, it helps to know that consecutive odd integers can be represented algebraically as k, k+2, k+4, k+6, etc (where each value is 2 greater than the one before it.

So, to solve this question, we can first make the following observations:
- w is the smallest integer.
- Since x is the next odd integer, we can say that x = w+2
- Since y is the next odd integer, we can say that y = w+4
- Since z is the next odd integer, we can say that z = w+6

The question asks, "w + x is how much less than y + z?"
In other words, [w + w+2] is how much less than [w+4 + w+6]?
When we simplify, we get [2w+2] is how much less than [2w+10]?, and we can see that the answer is 8

Cheers,
Brent