Answer
c. It divides the radius by 2.
Explanation
The general equation of a circle is
(x-h)² + (y-k)² = r²
Where (h, k) makes the coordinates of the circle and r the radius.
x² + y² = 25 For this equation,
center (0, 0)
Radius = √25 = 5
4x² + 4y² = 25 First simplify this equation
4x² + 4y² = 25 ⇒ x² + y² = 25/4
center (0, 0)
Radius = √(25/4) = 5/2
The radius has been divided by 2
