The derivative of a function may be used to determine whether the function is increasing or decreasing on any intervals in its domain. If f′(x) > 0 at each point in an interval I, then the function is said to be increasing on I. f′(x) < 0 at each point in an interval I, then the function is said to be decreasing on I.
Answer:
a) 3
b) 12
c) 4
Step-by-step explanation:
a)
17 - 4x = 8 - x
9 = 3x
x = 3
b)
3x ÷ 4 = 9
3x = 36
x = 12
c)
5x + 6 × (x + 2) = 56
5x + 6x + 12 = 56
11x = 44
x = 4
I think that the answer would be B