Question

find the radius of the circle X2+y2-6x+4y-12=0​

Answer 1

X²+y²-6x+4y-12=0

x²- 6x + y²+4y = 12

(x²- 6x +2²)+(y²+4y+2²) =12+2+2

(x+2)² +(y+2)² = 16= 4²

using formula (x+h)²+(y+k)² = r²

radius of the circle is 4