. 12312: jakie ma wspolrzedne srodek S o rownaniu x²+y²−4x−8y+4=0

gabi: x² +y² −2ax −2by +c =0 S(a,b) r² = a²+b² −c to : −2a= −4 => a= 2 −2b=−8 => b= 4 S(2,4)

ORZEŁ: y²−8y+16+x²−4x+4 −16=(y−4)²+(x−2)²=16 S(2,4) r=4

gabi: lub tak: x² −4x +4 −4 +y² −8x +16 −16 +4=0 ( x −2)² − 4 +( y−4)² − 16+4=0 (x−2(²+(y−4)² = 16 S(2,4) r=4