Time is your independent variable, and snowfall is your dependent variable.
Slope can be found by calculating ∆y/∆x:

Snowfall will accumulate 0.02 m every hour.
Solution:
The difference of cubes identity is
if a and b are any two real numbers, then difference of their cubes , when taken individually:
→a³ - b³= (a-b)(a² + a b + b²)→→→Option (D) is true option.
I will show you , how this identity is valid.
Taking R H S
(a-b)(a² +b²+ab)
= a (a² +b²+ab)-b(a² +b²+ab)
= a³ + a b² +a²b -b a² -b³ -ab²
Cancelling like terms , we get
= a³ - b³
= L H S
A random guess could be 495866 because if you round is to the nearest thousandths it will be 500000
Garden
max area is if the sides are as equal as possible
so he should try to make a square (ideal is a circle, but barn walls are normally straight)
squaer perimiter=4 times legnth of 1 side
perimiter=amount of fencing=80
80=4s
divide 4
20=s
one sides=20
area=legnth times width
in squaer, legnth=width
20=legnth
20=width
area=20 times 20=400
dimetions are 20ft by 20ft to give 400ft^2
(fun fact, if it were a circle, the area would be about 509.5ft^2)
answer is 20ft by 20ft and area=400ft^2