PreCalc help with sums. I will mark brainliest. (also can you explain WHY you got what answer you got? Thanks)

8

Step-by-step explanation:

a = -4

r = 16/-4 = -4

Sn = a(r^n - 1)/(r - 1)

52428 = -4[(-4)^n - 1]/(-4-1)

(-4)^n - 1 = 65535

(-4)^n = 65536

Means n is even

(4)^n = 65536

nln(4) = ln(65536)

n = 8

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

5

step-by-step explanation: