Since ED and DB are exactly half of EB, we can set ED and DB equal to each other.
x + 4 = 3x - 8
Subtract x from both sides. Add 8 to both sides
12 = 2x
Divide both sides by 2
6 = x
ED = 6 + 4 = 10
ED = DB = 10
EB = ED +DB = 10 + 10 = 20
ED = 10
DB = 10
EB = 20
