the answer is 2. see attached for step-by-step instructions. hope that helps!
Answer:

Step-by-step explanation:
<u>Given</u>
<u />
<u>Solution</u>
(1) Find the rate of the cube's edge length with respect to time at s=30:

(2) Find the rate of the cube's surface area with respect to time at s=30:

Therefore, the surface area increases when the length of an edge is 30 cm at a rate of
.
If the chalkboard is just rectangular we can just use:
(2 x L) + (2 x W)
or
L+L+W+W
L= Length
W= Width
Answer:
114 a month for 10 months
Step-by-step explanation: