Answer:
Option A,C
Explanation:
Concept involved

Here, thr length of intercept on y-axis
⇒ 2√f2−c
and if circle touches x-axis
⇒ g2=c
for x2+y2+2gx+2fy+c=0
here, x2+y2+2gx+2fy+c=0

Passes through (3,0)
⇒ 9+6g+c=0 ........(i)
g2=c ..........(ii)
and 2√f2−c=2√7
f2−c=7 .........(iii)
From Eqs .(i) and (ii), we get
g2+6g+9=0
(g+3)2 =0
g=-3
and c=9 ∴ f2=16
f=±4
∴ x2+y2−6x±8y+9=0