Each day that a library book is kept past its due date, a $0.30 fee is charged at midnight. which ordered pair is a viable solution if x represents the number of days that a library book is late and y represents the total fee?
a. (–3, –0.90)
b. (–2.5, –0.75)
c. (4.5, 1.35)
d. (8, 2.40)

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

-12 > a

step-by-step explanation:

-11 > 1 + a

subtract 1 from each side

-11 -1> 1 -1+ a

-12 > a