Answer:
the second one
Step-by-step explanation:
i did it in my head and double checked :)
Answer:
Perpendicular to base
Step-by-step explanation:
The cut creates two rectangular prisms (each angle must be 90 degrees)
The cut is perpendicular to the base
Answer:

Step-by-step explanation:

+8n +8n

Answer:
Step-by-step explanation:
You can look at it and see that 1/3 is added to each term. The common difference is 1/3. If you want to be be more formal,
d = d4 - d3
d = 0 - - 1/3
d = 0 + 1/3
d = 1/3
X is the number
sum means add
sum of half a number and 4 means
(x/2)+4
result is -16
(x/2)+4=-16
minus 4 both sides
x/2=-20
times 2 both sides
x=-40
the number is -40