For 3x + 12 + x, do like terms:
4x + 12
For 4(3 + x), multiply
12 + 4x
They are both the same, just written in different ways. One is adding like terms and the other is multiplying with parentheses. Even though it may be switched around, it is still the same.
Hope this helps :)
First case:
average of test score =70
number of students =p
total score of 'p' students = ( average of test score)*( number of students)
total score of 'p' students =70p
Second case:
average of test score =92
number of students =n
total score of 'n' students = ( average of test score)*( number of students)
total score of 'n' students =92n
total number of students = p+n
total average score =86
so, total score =86(p+n)
total score = total score of 'p' students +total score of 'n' students

now, we can simplify it



now, we can find p/n

................Answer
In general, the volume

has total derivative

If the cylinder's height is kept constant, then

and we have

which is to say,

and

are directly proportional by a factor equivalent to the lateral surface area of the cylinder (

).
Meanwhile, if the cylinder's radius is kept fixed, then

since

. In other words,

and

are directly proportional by a factor of the surface area of the cylinder's circular face (

).
Finally, the general case (

and

not constant), you can see from the total derivative that

is affected by both

and

in combination.
Answer:
-5.65
Step-by-step explanation: