How much does Kelly make an hour if she worked 35 hours and made $323.75 this
week?

$9.25 an hour

Step-by-step explanation:

625 metres

Step-by-step explanation:

Given the area function expressed as a(w)=-(w-25)^2+625.

The maximum area occurs at when da/dw = 0

da/dw = -2(w-25)

0 = -2(w-25)

-2(w-25) = 0

w - 25  = 0

w = 25

Substitute w = 25 into the modeled equation;

Recall a(w)=-(w-25)^2+625.

a(25)=-(25-25)^2+625

a(25) = 0+625

a(25) = 625

Hence the maximum area possible is 625 metres