Answer :

Answer: x=3.8x=3.8

Step-by-step explanation:

Since the triangles are congruent, the corresponding angles are equal. Thus, angle AA in △ABC△ABC is congruent to angle FF in △DEF△DEF. This gives us the equation:

2x+15∘=7x−4∘2x+15∘=7x−4∘

Let's solve this equation:

   Subtract 2x from both sides:

   15∘=5x−4∘

   Add 4∘4∘ to both sides:

   19∘=5x

   Divide by 5:

   x=195=3.8