You just purchased a cellular phone and are trying to decide the best cell phone company in which to give your business. when you contacted the talks-a-lot company, they were offering a monthly plan of $40 for 600 minutes and $0.35 for each minute exceeding the 600 minutes. in the sunday paper, you see an ad for the chat-away company, which offers a monthly plan of $50 for 600 minutes and $0.10 for each minute exceeding the 600 minutes. how many minutes would you have to talk over and above the 600 minutes for the cost to be the same with both companies and what would be the equal cost?

what golf ball

step-by-step explanation:

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

answer: a

step-by-step explanation: the answer is a due to the rule of symmetry; that a line of symmetry must divide a figure into 2 pieces that are the exact same, only reflected over a line of symmetry. b and c do not have lines of symmetry and would not divide the figure evenly, thus making the answer a.