The formula d=rt is used to calculate the distance an object travels over a period of time, t, at a
constant rate, r. Based on this formula, what is the
rate, r, in terms of d and t?
A) r = d/t
B)r = dt
C)r = t/d
D) r = r - t

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204