Answer:
See Explanation
Step-by-step explanation:
<em>Question like this are better answered if there are list of options; However, I'll simplify as far as the expression can be simplified</em>
Given

Required
Simplify

Represent
with a
Represent
with b
The expression becomes

Factorize



Recall that

The expression
becomes

..............................................................................................................................
In trigonometry

Subtract
from both sides


..............................................................................................................................
Substitute 1 for
in 

Open Bracket
------------------This is an equivalence

Solving further;
................................................................................................................................
In trigonometry


Substitute the expressions for secx and tanx
................................................................................................................................
becomes

Open bracket


Add Fraction
------------------------ This is another equivalence
................................................................................................................................
In trigonometry

Make
the subject of formula

................................................................................................................................
Substitute the expressions for
for 

Open bracket

---------------------- This is another equivalence
7 is 1/4 of 28, so 7 is 25% of 28.
The drop from 28 to 7 is a drop of 21.
21 is 3 times 7, so 21 is 3 times 25%.
Answer: It is a 75% decrease.
You would want to sell the bag of candy in ounces, unless you have way too much candy.
8.8 squared + 9.5 squared = square root 12.94 rounded 12.1