Answer: x = 3.5
Step-by-Step Solution:
Let us first label the figure.
Let the Triangle be ABC with a line DE || BC.
Now, in ∆ABC,
DE || BC (given)
=> AD/DB = AE/EC (by B.P.T)
Substituting the given values,
AD/DB = AE/EC
2/4 = x/7
1/2 = x/7
2x = 7
x = 7/2
=> x = 3.5
Therefore, x = 3.5