Answer:
It divides the radius by 2, which is the last option in your list of possible answers.
Step-by-step explanation:
Recall that the standard equation of a circle of radius R centered at the origin of coordinates is given by:
[tex]x^2+y^2=R^2[/tex]
so when you have the first equation of the circle:
[tex]x^2+y^2=R^2\\x^2+y^2=25\\x^2+y^2=5^2[/tex]
The radius of the circle was 5
Now, when you work with the second equation, we need to divide both sides by 4 in order to get the standard form of the circle and be able to understand what the radius is:
[tex]4x^2+4y^2=25\\x^2+y^2=\frac{25}{4} \\x^2+y^2=(\frac{5}{2})^2[/tex]
So we see that the initial radius 5 is now divided by 2.
