108 = -12 + -4(-5n + 7)
108 = -12 + (7 * -4 + -5n * -4)
108 = -12 + (-28 + 20n)
108 = -40 + 20n
-20n = -40 + -108
-20n = -148
n = 7.4
You gave little context, so here is a few solutions.
POSSIBLE #1:
assuming s is a variable
---> Simplify
×
to 

---> Collect like terms.

---> Simplify.

POSSIBLE #2: (assuming s is not relevant)
Simplifying
4x + -12 = 16 + 8x
Reorder the terms:
-12 + 4x = 16 + 8x
Solving
-12 + 4x = 16 + 8x
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-8x' to each side of the equation.
-12 + 4x + -8x = 16 + 8x + -8x
Combine like terms: 4x + -8x = -4x
-12 + -4x = 16 + 8x + -8x
Combine like terms: 8x + -8x = 0
-12 + -4x = 16 + 0
-12 + -4x = 16
Add '12' to each side of the equation.
-12 + 12 + -4x = 16 + 12
Combine like terms: -12 + 12 = 0
0 + -4x = 16 + 12
-4x = 16 + 12
Combine like terms: 16 + 12 = 28
-4x = 28
Divide each side by '-4'.
x = -7
Simplifying
x = -7
If there are any other ways to solve this please add more context in the comments below this answer! Hope this was helpful! Have a marvelous day/night!
P(x) = 3000 + 1200x - 6x²
P'(x) = 1200 - 12x
1200 - 12x = 0
- 12x = - 1200
x = 100<span>
Shoutout to @dferreiraalves
Your answer is: x = 100
Have an amazing day and stay hopeful!
</span>
Answer:
Its C
Step-by-step explanation: