<u>Given</u>:
Given that we need to prove the identity 
<u>Proof</u>:
Step 1: Factor out the common term sin x, we get;

Step 2: Using the identity 

Step 3: Reciprocating sec x, we get;

Step 4: Splitting the denominator, we have;

Simplifying, we get;

Thus, the identity is proved.
Answer:
2x - xy = 0
Step-by-step explanation:
We need to solve the equations simultaneously to find the values of x and y:
x + y = 12
x - y = 8 - we need to add the equations together
2x = 20
x = 10
Then we substitute x into one of the equations to find y:
10 + y = 12
12 - 10 = y
y = 2
Now we substitute x and y into the final expression:
2(10) - 2(10)
20 - 20 = 0
The volume is 40
8x1x5=40
:)))))))))))))))))))))))
Jacob is correct in thinking that because the mean represents the average of several quantities
It would be -25% !!!!!!!!