$1351.58 is the correct answer
You can use the arithmetic sequence sum formula here:

Where d = 4
n = 15

= 4i-1
Then, plug the values in, and you should get
465
Answer: x =8
Step-by-step explanation:
-12 + 9x = 60 (the other angles are 60, 180 - (60 + 60) = 60)
9x = 72
x = 8
The volume of the cube
V = s^3
Where s is the side length
V = s^3
V = 5^3
V = 125 cu in
Surface area of cube
A = 6s^2
Where s is the side length of the cube
A = 6s^2
A = 6(5^2)
A = 6(25)
A = 150 sq in