Answer:
BD measures 20 units.
Explanation:
We are given that Point C is on the line segment BD, where:

And we want to determine the numerical length of BD.
Since C is somewhere on BD, BD is the sum of BC and CD:

Substitute:

Solve for x. Subtract:

Hence, the value of x is 4.
BD is given by 5x. Therefore:

In conclusion, BD measures 20 units.