Answer :
Answer:
56.4 degrees
Step-by-step explanation:
To find mED, we need to use the angle sum property of a triangle, which states that the sum of the angles in a triangle is 180 degrees. In this case, we have angles E, B, and C in triangle EBC.
1. Set up the equation:
mED + mBF + mBCF = 180
2. Substitute the given expressions into the equation:
(9x - 3) + (15x - 39) + (11x - 9) = 180
3. Combine like terms:
9x - 3 + 15x - 39 + 11x - 9 = 180
35x - 51 = 180
4. Solve for x:
35x = 231
x = 231/35
x = 6.6
5. Substitute x back into the expression for mED:
mED = 9x - 3
mED = 9(6.6) - 3
mED = 59.4 - 3
mED = 56.4
Therefore, mED is 56.4 degrees.
