They are similar because they both contain variables.
Answer:

Step-by-step explanation:
So we have the expression:

Distribute. Multiply (4x+5) to each term:

Distribute:

Combine like terms:

Add and simplify:

And this is in descending order, so it's in standard form.
Answer:
C
Step-by-step explanation:
Answer:
0
Step-by-step explanation:
Answer:
, 
Step-by-step explanation:
Given
the equation is 
completing the square

Thus, the center of the circle is
and radius is 