Answer:
a = -2 and b=4 and c = -4
Step-by-step explanation:
the center is : A(1 ; -2)
B(1 ; 1) in this circle so ; AB= r ( ridus)...r =3
note :
an equation of the circle Center at the A(1,-2) and ridus : r is :
(x-1)² +(y+2)² = 3²
x²-2x+1 +y²+4y +4-9 =0
x²+y² -2x+4y -4 = 0 so : a = -2 and b=4 and c = -4
