A phone company offers two monthly plans. Plan A costs $14 plus an additional $0.15 for each minute of calls. Plan B costs $25 plus an additional $0.13 for each minute of calls. For what amount of calling do the two plans cost the same?

What is the cost when the two plans cost the same?

1. credits

2. dual - aspect

hope i : )

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

30005

yes ok