Add the following complex numbers: (3-9i) + (6-21i)
A. 9-7i
B. 9-11i
c. -3-71
D. -3-11i

he sells x mount because thats eqivilqant to the maz and then divided into quarters

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

i those same problems in math and dont know how to do them