The mathematical expression in this case is
(x+3)/2
Answer:

Step-by-step explanation:
To calculate the angles of the given triangle, we can use the law of cosines:

Then, given the sides a=2, b=9, and c=8.

For B:

Answer:
It is given that the volume of a cone =
cubic units
Volume of cone with radius 'r' and height 'h' = 
Equating the given volumes, we get

× 

It is given that the height is 'x' units.
Therefore, 

Therefore, 
So, the expression '
' represents the radius of the cone's base in units.