Answer:
Standard form: 
Center: 
Radius:
Step-by-step explanation:
The equation of a circle in the standard form is

Where the point (h, k) is the center of the circle
To transform this equation
this equation in the standard form we use the method of square.
First, we group similar variables

Divide both sides of equality by 4

Now we complete square for variable x.
Take the coefficient "b" that accompanies the variable x and divide by 2. Then, elevate the result to the square:

Now add
on both sides of the equality

Factor the expression and simplify the independent terms


Then

and the center is 
radius