51-38=8 and 44-38=8 are both equivalent
For Commutative Property of Addition
Let us take a decimal number
and a fraction 
Now, according to the Commutative property of Addition:
For any two numbers
and
:

So, for
and 
Let us add


Also,


Therefore, 
Hence, Commutative Property of Addition is satisfied.
For Associated Property of Addition
Let us take two same decimal numbers
,
and a fraction 
Now, according to the Associated property of Addition:
For any three numbers
,
and 

So, for
,
and 
The Left hand side:







The Right hand side:






Thus,

Therefore, 
Hence, Associative Property of Addition is satisfied.
$32,750 + $375 = 33125
$33,125 * .06= 1987.50
$33,125+$1987.50= $35,112.50
$35,112.50+$50=$35,162.50
A. $35,162.50
We know that
[surface area for a rectangular prism with a square base ]=2*s²+4*s*h
2*s²----> Is the surface area of the bases
4*s*h---> is the lateral area
s=2 units
h=4 units
[surface area for a rectangular prism with a square base ]=2*2²+4*2*4
surface area=8+32----> 40 units²
the answer is
40 units²