Answer:
The answer to your question is EF = 12
Step-by-step explanation:
Data
DE = 6x
EF = 4x
DF = 30
Process
DE + EF = DF
6x + 4x = 30
10x = 30
x = 30 / 10
x = 3
6(3) + 4 (3) = 30
18 + 12 = 30
30 = 30
DE = 6(3) = 18
EF = 4(3) = 12
