C. x³-4x²-16x+24.
In order to solve this problem we have to use the product of the polynomials where each monomial of the first polynomial is multiplied by all the monomials that form the second polynomial. Afterwards, the similar monomials are added or subtracted.
Multiply the polynomials (x-6)(x²+2x-4)
Multiply eac monomial of the first polynomial by all the monimials of the second polynomial:
(x)(x²)+x(2x)-(x)(4) - (6)(x²) - (6)(2x) - (6)(-4)
x³+2x²-4x -6x²-12x+24
Ordering the similar monomials:
x³+(2x²-6x²)+(-4x - 12x)+24
Getting as result:
x³-4x²-16x+24

Here I have included 3 methods: Differentiating, Integrating and factorize
Differentiating:




Integrating:


Factorise:

460 (envelopes) / 30 (minutes) = 15.3 rounds down to 15 envelopes per minute
D because of lx w x h and you would get one cubic unit
Answer:

The graph in the attached figure
Step-by-step explanation:
Let
x ----> the number of days
y ----> the amount of money in her bank account
we know that
The equation of the line in slope intercept form is equal to

where
m is the slope or rate
b is the y-intercept or initial value
In this problem we have
The slope is equal to
----> is negative because is a decreasing function
----> initial amount in the account bank
substitute

see the attached figure to better understand the problem