Step-by-step explanation:
Annie = x
Brianna = y
Carly = z
Now,
x + y + z = 105 ...(1)
Carly has sold ten more than three times Brianna's sales.
z = 10 + 3y ...(2)
Brianna sold five more than Annie.
y = 5 + x ...(3)
Now,
z = 10 + 3y
z = 10 + 3(5 + x)
z = 10 + 15 + 3x
z = 25 + 3x
Now,
x + y + z = 105
x + (5 + x) + 25 + 3x = 105
5x + 30 = 105
5x = 105 - 30
5x = 75
5x/5 = 75/5
x = 15
So,
y = 5 + x
y = 5 + 15
y = 20
Now,
z = 25 + 3x
z = 25 + 3(15)
z = 25 + 45
z = 70
Thus,
Annie Sold 15 boxes
Brianna Sold 20 boxes
Carly Sold 70 boxes
A function

is periodic if there is some constant

such that

for all

in the domain of

. Then

is the "period" of

.
Example:
If

, then we have

, and so

is periodic with period

.
It gets a bit more complicated for a function like yours. We're looking for

such that

Expanding on the left, you have

and

It follows that the following must be satisfied:

The first two equations are satisfied whenever

, or more generally, when

and

(i.e. any multiple of 4).
The second two are satisfied whenever

, and more generally when

with

(any multiple of 10/7).
It then follows that all four equations will be satisfied whenever the two sets above intersect. This happens when

is any common multiple of 4 and 10/7. The least positive one would be 20, which means the period for your function is 20.
Let's verify:


More generally, it can be shown that

is periodic with period

.
Base of the exponential equation should be (-1).
And finally the product or result should also be a negative number.
Let us take a variable for n natural numbers.
(Note: All positive whole numbers are called natural numbers that is 1,2,3,4,5,....).
In order to get the expression, we need to find the expession for odd natural numbers.
We know,
The expession for odd natural numbers is given by = 2n-1.
Where n= 1,2,3,4,5...
If we have an odd exponent of a negative number, it always gives a negative number.
We got, base = -1 ( a negative number) and
exponent = (2n-1) ........... expression for odd number.
Therefore, we could write final exponential expression that would give a negative for all natural numbers.

A scale factor of 1.25, also written as 1 1/4 should be used