Hitunglah berapa nilai-nilai A, B dan C. Jika lingkaran x2 + y2 + Ax + By + C = 0 melalui (3,5), (-2,4) dan (-6,-2)

(3-a)²+(5-b)²=r²
9-6a+a²+25-10b+b² = r²
a²+b²-6a-10b+34 = r²

(-2-a)²+(4-b) ²=r²
4+4a+a²+16-8b+b²=r²
a²+b²+4a-8b+20=r²

(-6-a)²+(-2-b)²=r²
36+12a+a²+4+4b+b²=r²
a²+b²+12a+4b+40=r²

a²+b²-6a-10b+34 = r²
a²+b²+4a-8b+20 = r²
------------------------------- -
-10a-2b+14 = 0
5a + b = 7

a²+b²+4a-8b+20 =r²
a²+b²+12a+4b+40=r²
------------------------------ -
-8a-12b-20 = 0
2a+3b = -5

5a + b = 7 x3 15a+3b = 21
2a+3b = -5. 2a+3b = -5
------------------ -
13a. = -26
a = -2
5(-2)+b = 7
b = 17

r² = (3+2)²+(5-17)²
= 25+144
= 169

Pers :
(x+2)²+(y-17)² = 169
x²+4x+4+y²-34y+189 = 169
x²+y²+4x-34y +24 = 0

A = 4
B = -34
C = 24