Answer:
When the input is 6, the output must be 12.
Step-by-step explanation:
f(6) = 12
The input to the function is x which is 6 and the output is what f(6) equals which is 12
Answer:
45.8
Step-by-step explanation:
We need to find the surface area for this entire figure!
We can see that this is a pyramid here - we must find the area of the 3 triangles and the base triangle at the bottom.
The 3 triangles building up the pyramid are all equal to each other.
To find the area of a triangle, use 

Round to the nearest tenth: 45.75 -> 45.8
I get:
24 = 3x-12
add 12 to both sides
36 = 3x
divide each side by 3 and you will get 12