Look for the consistencies here. Both of these addition problems contain the values 7,4, and 5 which is equal to 16. So, if we subtract 16 from 32, we can see that X+Y=16 in the first column. And, if we subtract 16 from 52, we see that in the second column X+Z=36. We are looking for the value of Z-Y. We can get that because if we have X+Z=36 and subtract X+Y=16 from it, we find that Z-Y=20.