The leading term of polynomial function is the the term contain highest degree so here in the given question leading term is 
and leading coefficient is the coefficient of the term with greatest exponent -3
RULES for End behaviour
we have following four cases
CASE1: Even degree and positive leading coefficient


CASE2: Even degree and negative leading coefficient


CASE3: Odd degree and positive leading coefficient


CASE4: Odd degree and negative leading coefficient

Here in the given case we have odd degree and negative leading coefficient

I = p * r * n
i is the interest
p is the principal
r is the interest rate per time period
n is the number of time periods.
in your problem:
i = 900
p = 2000
r = what you want to find
n = 3 years
formula becomes 900 = 2000 * r * 3
solve for r to get r = 900 / 2000 / 3 = .15
that's .15 interest rate per year = 15% per year.
at a nominal interest rate of .15 per year, the interest rate per month would be .15/12 = .0125 per month.
the remaining balance at the end of 6 month is equal to 1907.140183
An = a1 + (n - 1)(d)
Where a1 is the first term and d is the common difference.
First find d, the common difference.
24, ____, 32
a3 a4 a5
Subtract 32-24 = 8
Subtract a5 - a3 = 2
Divide 8/2 = 4
d = 4
Use d and one of the values they give us to find a1.
a3 = 24
24 = a1 + (3 - 1)(4)
24 = a1 + 2(4)
24 = a1 + 8
Subtract 8 from both sides
16 = a1
an = 16 + (n - 1)(4)
Can also be written
an = 16 + 4n - 4
an = 4n + 12