Question

Which equation represents the general form a circle with a center at (–2, –3) and a diameter of 8 units?

x2 + y2 + 4x + 6y – 51 = 0
x² + y² – 4x – 6y – 51 = 0
x2 + y2 + 4x + 6y – 3 = 0
x2 + y2 – 4x – 6y – 3 = 0

Answer 1

Center (h,k)=(-2,-3) so equation is (x+2)^2+(y+3)^2=4^2=16. Expanding gives x^2+y^2+4x+6y-3=0.

So the correct choice is: x^2 + y^2 + 4x + 6y – 3 = 0.