Answer:
29
Explanation:
To solve this we have to add corresponding line segments and make them equal to each other.
We can see XZ is broken into XA and AZ.
We can also see that WY is broken into WA and AY.
We are given:
XA=12
AY=14
WA=3+3x
AZ=4x+1
So, we combine and make them equal to each based on their whole line segments:

combine like terms

subtract 13 from both sides

subtract 3x from both sides
x=4
We aren't done yet, because the question is asking us to find XZ which is 12+4x+1:
substitute 4 for x
12+4(4)+1
multiply
12+16+1
=29
So, XZ is 29 units.
Hope this helps! :)