Answer:
Step-by-step explanation:
note : (ax)' = a
(b)' = 0
f(x) = x-5. so : f'(x) = 1
x=23
Simplifying
(3x + -50) + (7x)
Reorder the terms:
(-50 + 3x) + (7x)
Remove parenthesis around (-50 + 3x)
-50 + 3x + (7x) =
Combine like terms: 3x + (7x)
-50 + 10x
Solving
-50 + 10x
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '50' to each side of the equation.
-50 + 50 + 10x = 180 + 50
Combine like terms: -50 + 50 = 0
0 + 10x = 180 + 50
10x = 180 + 50
Combine like terms: 180 + 50 = 230
10x = 230
Divide each side by '10'.
Simplifying
x = 23
3 hours is the correct answer
I think I might be wrong but try 25% (but like I said probably wrong)
80 / 100 = 1.25
100 - 80 = 20
So, 1.25 x 20 = 25%