Acircle with two chords is shown below. the diagram is not drawn to scale. what is the value of x? round the answer to the nearest tenth.
a: x=15.8
b: x=5.1
c: x=189.0
d: x=28.0

 The correct option is (A) x = 15.8 units.

Step-by-step explanation:  As given in the question, the chords AB and CD of a circle intersect at the point E. See the modified attached figure.

Also, AE = 9 units, EB = 21 units, CE = 12 units  and  ED = x.

We are to find the value of x.

Chord Intersecting Theorem:  This theorem gives a relation of the four line segments created by two intersecting chords in a circle, which states that the products of the lengths of the line segments on each chord are equal.

Applying the above theorem in the given situation, we can write

Rounding to the nearest tenth, we get

x = 15.8 units.

Thus, the value of x is 15.8 units.

Option (A) is CORRECT.