(8/-4) / (-3/9)=
(8/-4) * (9/3)=
72/-12=
-6
Answer:
$74.68
Step-by-step explanation:
Convert the percent to a decimal.
4% = 0.04
Multiply his income by the percentage to find the tax.
$1,867 × 0.04 = $74.68
He can expect to pay $74.68.
Since they tell us that Q is the midpoint you now understand that the line is split evenly.
PQ=QR
2x+3=3x-2
2x+5=3x
x=5.
You just need to plug those expressions inside the formula: it doesn't matter if they're expressions involving a variable instead of plain numbers: the formula becomes

If you want, you can simplify it by expanding the square and then multiply the two parenthesis:

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

.