18 / 12 = 3 / 2 (in simplest form).
-25-6=-31
Change the subtraction sign into positive and add 25 and 6, then put the negative sign after.
Answer:
D
Step-by-step explanation:
1. The surface area of a cone S is S=

, where r is the radius of the base and l is the slant height.
2. The slant height l is found as follows:



3.


4. The answer is C