Question

Which equation represents a circle?

Answer 1

Answer:

Option C

Step-by-step explanation:

Equation of a circle is in the form of

$(x-h)^2+(y-k)^2= r^2$ where (h,k) is the center and r is the radius of the circle.

For equation of a circle, the denominator should be same

first , second and fourth equation have different denominators. so they are not equation of circles.

2^2 is 4

Multiply the whole equation by 4

So the equation becomes

$x^2+y^2= 4$ that represents the equation of a circle

Answer 2

C. Multiple each side by 4 and you get the radius as 2 and the center at 0,0.