Answer: Technically, it would be 9/3, but you can simplify that to 3.
Multiply the amount of the notebooks which is 3, by the cost of the notebook, which is $15.85. that is $47.55.
to find how much it costs with the coupon, do the notebook cost and subtract that by 0.75
$47.55 - 0.75 = $46.8
Everything has been explained in there
Answer:

Step-by-step explanation:
Given : 
We have to write which identity we will use to prove the given statement.
Consider 
Take left hand side of given expression 
We know

Comparing , we get, a= 180° and b = q
Substitute , we get,

Also, we know
and 
Substitute, we get,

Simplify , we get,

Hence, use difference identity to prove the given result.