A newspaper invited readers to call a telephone number and record their comments. The next day they reported that readers overwhelmingly prefer two-way traffic flow to one-way streets. This is an example of: A. A convenience sample B. A self-selected sample C. A systematic sample D. A random sample​

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

yes

step-by-step explanation:

yes