We are given a triangle and told that line WY is a perpendicular bisector to side XZ. This line basically splits the triangle into two triangles: XYW and YZW.
Note that as both triangles have two pairs of sides with the same length and a congruent angle (angles XWY and YWZ are both 90°), both triangles are congruent. THat is, corresponding sides have the same length.
This leads to having sides XY and YZ to be congruent. So we have the equation
![12x\text{ -5=129}](https://img.qammunity.org/2023/formulas/mathematics/college/9v75xapyhpyeo4ymqhgpfs5r0u2dr2m2uj.png)
first, we add 5 on both sides. So we get
![12x=129+5=134](https://img.qammunity.org/2023/formulas/mathematics/college/mndgdac2k1zv55nwjj5cisg3gw91chdone.png)
Finally, we divide both sides by 12. We get
![x=(134)/(12)](https://img.qammunity.org/2023/formulas/mathematics/college/coywp2rgfgg3w75d0vbi7dpit3ru9bnh9q.png)
Note that
![x=(132+2)/(12)=(132)/(12)+(2)/(12)=11+(1)/(6)](https://img.qammunity.org/2023/formulas/mathematics/college/ee68f5fqshynf96q5srd76lk33jo40t8g9.png)
so we have that
![x=11(1)/(6)](https://img.qammunity.org/2023/formulas/mathematics/college/ar11a28qyxp6hfb8peucmbqfz7j29skqzm.png)