Answer:
an average 7th grader owns 3 pairs of sneakers
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

.
Given expression in exponential form :
.
We need to convert it into radical form.
<em>Please note: When we convert an exponential to radical form, the top number goes in the exponent of the term and bottom number of the fraction goes in the radical sign to make it nth radical.</em>
We can apply following rule:
.
Therefore,
.
Therefore, correct option is : D. ninth root of a to the fourth power.
4/3
explanation : just write it in fraction form
B = 2A/h
The way you would get this is first by clearing the fraction. So in order to clear the fraction, you have to multiply the equation by the denominator.
2(A = 1/2bh)
2A = 1bh
2A = bh
Then you have to isolate the variable. So you'd divide bh by h in order to get b by itself. So you'd end up with:
2A/h = bh/h
2A/h = b