Draw out a number line with the values 0, 5, 10, 15, 20, 25, 30, etc (basically multiples of 5)
Then plot a point at 25
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Or you can draw out a number line with the multiples of 10, so with the values 0, 10, 20, 30, ...
Then plot a point at the exact midway point between 20 and 30 to represent the value 25
It's D, 3-2i.
Hope this helps
Answer:
The maximum revenue is $900, obtained with 30 people
Step-by-step explanation:
Naturally, the answer should be a number equal or higher than 20, because up to 20 persons, each one pays the same. Lets define a revenue function for x greater than or equal to 20.
f(x) = x*(40-(x-20)) = -x²+60x
Note that f multiplies the number of persons by how much would they pay (here, assuming that there are more than 20).
f is quadratic with negative main coefficient and its maximum value will be reached at the vertex.
The value of the x coordinate of the vertex is -b/2a = -60/-2 = 30
for x = 30, f(x) = 30*(40-(30-20))=30*30=900
So the maximum revenue is $900.
