F=x-48 over 4x. I hope that is right :)
Answer:

Step-by-step explanation:




<em>*Remember that A = angle and S = side.</em>
So remember that <u>similar figures have congruent angles and proportional sides.</u> Looking at triangles ABC and DEF, they both share 85° and 30° angles. <u>With this, the two triangles are similar by AA, or the first option.</u>