hello :
an equation of the circle Center at the A(a,b) and ridus : r is :
(x-a)² +(y-b)² = r²
in this exercice : a = -2 and b = 1 (Center at the A(-2,1))
r = AP......P( -4 , 1)
r² = (AP)²
r² = (4+2)² +(1-1)² = 36
an equation of the circle that satisfies the stated conditions.
Center at A(-2,1), passing through P(-4, 1) is : (x+2)² +(y-1)² = 36