The sum of all integral value(s) of ' r ' for which the circles x2+y2−10x+16y+89−r2=0 and x2+y2+6x−14y+42=0 intersect in two real distinct points is

We have (x−5)2+(y+8)2=25+64+r2−89 And (x+3)2+(y−7)2=49+9−42=16⇒(x−5)2+(y+8)2=r2 and (x+3)2+(y−7)2=(4)2⇒(5,−8) (−3,7)⇒65+225=289=17= distance between their centres  Now, |r−4|<1717⇒r>13 And −17