Answer:
x=8
Explanation:
Since the two parallelograms are similar, their corresponding sides should be proportionate. Therefore, we can set up a proportion to help us solve for x. That'll be AB/WX=AD/WZ, since those match up the corresponding sides.
4/18=6/4x-5
4(4x-5)=108
16x-20=108
16x=128
x=8