You have:
2r
6r-21
then move the 6r over to the left and you end up wtih
-4r
-21
Then you divide by -4 and when you do you must flip the inequality so your answer would be
r
21/4
The shaded squares are positive because a negative number multiplied or divided by a negative number makes the product or quotient positive. There is no specific rule that comes to mind, but if your teacher has provided a list of specific rules I would look for something mentioning negative numbers.
For this case we have a quadratic polynomial given by:
Where:
We must factor, for this we follow the steps below:
Step 1:
The term of the medium must be rewritten as the sum of two terms, whose sum is -7 and the product is 
:
Then, the term of the medium, fulfilling the two previous conditions, can be written as:
We check:
So, we have:
Step 2:
The maximum common denominator (the largest integer that divides them without leaving residue) of each group is factored
Step 3:
We take common factor 
:
Thus, the expression 
can be factored as:
Answer:
Such a ray that divides an angle into two equal angles is called an angle bisector.
Likewise, two rays that divide an angle into three congruent angles are called angle trisectors. Figure %:
An angle bisected and trisected On the left, angle ABC is bisected by the ray BD.
Credits to google.
In short, no.
