Question

What’s the answer to these?

Answer 1

Hello,

$x^2+y^2-4x+2y-4=0\\\\<=> (x-2)^2-2^2+(y+1)^2-1^2-4=0 \\ \\<=>(x-2)^2+(y+1)^2=9$

$(x+2)^2+(y-3)^2=9\\\\<=> x^2+4x+4+y^2-6y+9=9\\ \\<=>x^2+y^2+4x-6y+4=0$

Thanks