<span>A-4
Substitute 16 for a
16-4
Subtract
Final Answer: 12</span>
Two or zero expresses the possible number of positive real solutions for the given polynomial equation.
Answer: Option D
<u>Step-by-step explanation:</u>
Given equation:

First, we put hit and trial method to find out the one solution. So, if we put x=4 then the above expression will become zero. We can also write the above expression as

We know the formula,
, make use of this, we get

So, 
Hence, from the above expression, we have three values of x as x= 4, 2.64 and -2.64