It's not clear where point Y is located. If Y is the midpoint, and Y is on line XZ, then we can say that XY = 25 and YZ = 25 (since Y cuts XZ in half; the two equal portions are XY and YZ)
I'm using the segment addition postulate XY+YZ = XZ
However, all of this is based on the assumption that Y is the midpoint and on line XZ.
Answer:

Step-by-step explanation:
We can set up the following proportion and solve for length (
):

Answer: D
Step-by-step explanation:
You haven't shared "the given value of x," or, if you have, you haven't drawn attention to it.
Just suppose we were to choose x = 4 as a possible solution and then try to find a value of the parameter k that would make x = 4 an actual solution.
2(4) + 4k - 9 = (4)(4) - (4) + 1
Then 8 + 4k - 9 = 16 - 4 + 1, or 4k - 1 = 13. Then 4k = 14, and k = 14/4, or (after reduction) k = 7/2
If the parameter k equals 7/2, then x = 4 is a solution to the given equation.
To check this out further, start with the proposed solution x = 5 and find k.