Equation of circle whose radius is 5 and which touches the circle x2+y2−4x+6y−12=0 at     (-2,0) is

x2+y2−4x+6y−12=0 C1=(2,−3),r1=4+9+12=5 ,  r2=5 ⇒ Circles touch externally Let P(−2,0)  and C2  be the centre of required circle P=C1+C22⇒C2=2P−C1 =(−6,3) ∴ Eq.of circle is (x+6)2+(y−3)2=25