This question is incomplete, the diagram is missing. The complete diagram is uploaded along this answer.
Answer: (3) 2.5
Step-by-step explanation:
From the diagram, given that;
BF = 2.3, DF = x, FC = 5, FE = 4.6,
Now
by theorem
BF * FC = DF * FE
so we substitute
2.3 * 5 = x * 4.6
11.5 = 4.6x
x = 11.5 / 4.6
x = 2.5
therefore the value of x is 2.5
