Answer:
 8
Explanation:
The fact that DE is perpendicular to AC means triangles AED and CED are congruent and side AD is equal in length to side CD.
 5x -20 = 2x +4
 3x = 24 . . . . . . . add 20-2x
 x = 8 . . . . . . . . . .divide by 3
The value of x is 8.