Let's begin by listing out the information given to us:

We are to find the value of y
Answer:
Figures A, C, and D. B isn't one since it is curved
Answer:
C
Step-by-step explanation:
Volume = Length times Width times height
Volume = 3 1/2 * 1 1/2 * 4
3 1/2 * 1 1/2 * 4 = 21
Hence, the answer is C
PEMDAS.
Parentheses
Exponents
Multiplication
Division
Addition
Subtraction
Lets apply that here.
72-[(3x2^3)+48]
So first we start with (3x2^3)
2^3=8
3*8=24
now we do 24+48 which equals 72
now we have 72-72 which equals zero.
So
72-[(3x2^3)+48] = 0
Perimeter = 4 x sides
48 = 4 (x + 3)
48 = 4x + 12
36 = 4x
x = 9
Check:
x + 3 = 9 + 3 = 12
12 x 4 = 48