Answer:
Answer C
Step-by-step explanation:
Notice that 5 can be written as 1 + 1 + 1 + 1 + 1
and - 3x can be written as -x -x -x
and on the other side of the equal sign, you have 2x which is the same as: x + x
So answer C is the correct answer.
The greatest common factor would be 14x^2 because 2 is the gretest power in common between the x variables and 14 is the greatest factor betwern the two leading coefficients. When factored using this greatest common factor this is the result:

I hope this helps!
A square has four sides
If you have a box and count each flat part they will be four sides
A regular pentagon has 5 sides, all of equal length.
Simply multiply 17 by 5
The answer is 85