Question 822651
1)x^2+y^2-8x-2y+7=0
complete the square
x^2-8x+16 +y^2-2y+1 = -7 +16 +1
(x-4)^2 +(y-1)^2 = ((10)^(1/2))^2
this is a circle with center (4, 1) and radius square root of 10
2)x^2+y^2-3x-7y+12=0
complete the square
x^2-3x+9/4 +y^2-7y+49/4 = -12 +9/4 +49/4
(x-3/2)^2 +(y-7/2)^2 = ((10/4)^1/2)^2
this is a circle with center (3/2, 7/2) and radius square root of 10/4