Answer:
The center of the circle is
[tex](-\frac{3}{2},2)[/tex]
Step-by-step explanation:
Let the equation of the circle be
[tex]x^2+y^2+2ax+2by+c=0[/tex], where (-a,-b) is the center of this circle.
The points lying the circle must satisfy the equation of this circle.
A(0,0)
We substitute this point to get;
[tex]0^2+0^2+2a(0)+2b(0)+c=0[/tex]
[tex]\implies c=0[/tex]
B(-3,0)
[tex](-3)^2+0^2+2a(-3)+2b(0)+c=0[/tex]
[tex]\implies 9+0-6a+0+c=0[/tex]
[tex]\implies -6a+c=-9[/tex]
But c=0
[tex]\implies -6a=-9[/tex]
[tex]\implies a=\frac{3}{2}[/tex]
C(1,2)
[tex]1^2+2^2+2a(1)+2b(2)+c=0[/tex]
[tex]1+4+2a+4b+c=0[/tex]
[tex]2a+4b+c=-5[/tex]
Put the value of 'a' and 'c' to find 'b'
[tex]2(\frac{3}{2})+4b+0=-5[/tex]
[tex]3+4b+0=-5[/tex]
[tex]4b=-5-3[/tex]
[tex]4b=-8[/tex]
b=-2
Hence the center of the circle is
[tex](-\frac{3}{2},2)[/tex]