Which of the following numbers must be added to complete the square in the equation below?
x^2 +9x+15 = 11
A.-81/4
B.9/2
C.81/4
D. 81

C

Step-by-step explanation:

Take the coefficient of the linear term and divide it by 2

9/2

Then square it 81/4

That should either be added to the 11 or subtracted from the 15.

The answer is C

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

i believe that the slope of the line is -5

step-by-step explanation: