Rapid Rental Car charges a $35 rental fee, $15 for gas, and $0.25 per mile driven. For the same car, Capital Cars charges $40 for rental and gas and $0.35 per mile.
Part 1 out of 2
For how many miles is the rental cost at both companies the same?
The rental costs at both companies are the same at Miles.

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