Answer:
50
Explanation:
Since M is the midpoint of XY, this means that XM and MY must be equivalent from the definition of midpoint.
So:
![XM=MY](https://img.qammunity.org/2021/formulas/mathematics/high-school/eu1m5hqx2wk5cgzkfdoqhm8wda22ab3f7s.png)
The entire length of the segment (XY) is:
![XY=XM+MY](https://img.qammunity.org/2021/formulas/mathematics/high-school/dinh43ylg5oy7jildhsj1mt1v822n42gjo.png)
We know that XM is equivalent to MY. Substitute MY for XM:
![XY=MY+MY](https://img.qammunity.org/2021/formulas/mathematics/high-school/eu7w3vc3yiddo84mo6f80xxagisc30tr24.png)
Combine like terms;
![XY=2MY](https://img.qammunity.org/2021/formulas/mathematics/high-school/1exggqeqtevnpdjftmwlmd4ju3hb5208yz.png)
We are told that YM (or MY) is 25. So:
![XY=2(25)](https://img.qammunity.org/2021/formulas/mathematics/high-school/rcxxi7lq76liqvx7hwgkxw36qetbiliahp.png)
Multiply:
![XY=50](https://img.qammunity.org/2021/formulas/mathematics/high-school/zk8aicrmmgfdngftv2bad6a1u288ieiwwn.png)
So, the length of XY is 50.
And we're done!