If K is the midpoint of ER, EK = x + 5, and ER = 4x + 2, what is the length of KR?

Step-by-step explanation:

EK = ½ER

x+5 = ½(4x+2)

x+5 = 2x+1

x=4

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