The equation in graphing form:
[tex](x-h)^2+(y-k)^2=r^2[/tex]
Use: [tex](*)\ a\pm b)^2=a^2\pm2ab+b^2[/tex]
[tex] x^2+y^2-12y+27=0\\\\x^2+y^2-2\cdot y\cdot6+27=0\\\\x^2+\underbrace{y^2-2\cdot y\cdot6+6^2}_{(*)}-6^2+27=0\\\\x^2+(y-6)^2-36+27=0\\\\x^2+(y-6)^2-9=0\ \ \ \ |+9\\\\x^2+(y-6)^2=9 [/tex]
Answer: d) x^2+(y-6)^2=9
