Part 1) Finding x
Note the double tickmarks for segments XY and YZ. This indicates the segments are the same length, which leads to point Y being the midpoint of segment XZ.
Therefore, XZ is twice as long as XY
XZ = 2*( XY )
XZ = 2*( 2x-1 )
XZ = 4x - 2
We also know that XZ = 2(3x-4) = 6x-8. Let's equate 4x-2 and 6x-8 and solve for x
6x-8 = 4x-2
6x-4x = -2+8
2x = 6
x = 6/3
x = 3
Answer is 3
=====================================
Part 2) Finding the length of YZ
The resut of part 1 (x = 3) is plugged into the equation for XY to get
XY = 2*x-1
XY = 2*3-1
XY = 6-1
XY = 5
Segment XY is 5 units long. So is segment YZ as these two segments are the same length (aka congruent).
Answer: 5
=====================================
Part 3) Finding the length of segment XZ
The answer from the previous part was 5. This doules to 5*2 = 10
-----
A longer way to get the same answer is to plug x = 3 into the XZ equation and we get...
XZ = 2*(3x-4)
XZ = 2*(3*3-4)
XZ = 2*(9-4)
XZ = 2*5
XZ = 10
and we get the same answer
Answer: 10