Answer:
9.
Step-by-step explanation:
So basically, we need to find out x. So we know that ZX = YW because ZY and XY are already congruent and it's just adding a three to the value because of YX. We can find out x.
ZX = YW
5x + 17 = 10 - 2x
x = -1
Then we can find out the value of ZX and YW by plugging in x.
5(-1) + 17 = ZX = YW = 12.
Then we see that YX is 3 so...
ZX = ZY + YX
12 = ZY + 3
ZY = 9
So the answer is 9.
