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.
Answer:
7
Step-by-step explanation:
Answer:
cos(400)
Step-by-step explanation:
Useful things:
Cofunction identity: sin(x)=cos(90-x)
Sine and cosine have period of 360 degrees.
So sin(50)=cos(40) by cofunction identity.
Since cosine has period of 360 degrees then cos(40)=cos(360+40).
That simplifies to cos(400).
Answer: 12.50$
Explanation: 5.25$ (per pound) and he wants 3 pounds so we multiply 5.25x3 which equals 15.75 and then we subtract 3.25 (because of the coupon) which makes your final answer 12.50$