If the two circles `x^(2) + y^(2) =4` and `x^(2) +y^(2) - 24x - 10y +a^(2) =0, a in I `, have exactly two common tangents then the number of possible integral values of a is `:`

There are two circles whose equation are x^(2)+y^(2)=9 and x^(2)+y^(2)-8x-6y+n^(2)=0,n in Z. If the two circles have exactly two common tangents,then the number of possible values of n is 2 (b) 8 (c) 9 (d) none of these

There are two circles whose equation are x^2+y^2=9 and x^2+y^2-8x-6y+n^2=0,n in Zdot If the two circles have exactly two common tangents, then the number of possible values of n is

There are two circles whose equation are x^2+y^2=9 and x^2+y^2-8x-6y+n^2=0,n in Zdot If the two circles have exactly two common tangents, then the number of possible values of n is (a)2 (b) 8 (c) 9 (d) none of these

There are two circles whose equation are x^2+y^2=9 and x^2+y^2-8x-6y+n^2=0,n in Zdot If the two circles have exactly two common tangents, then the number of possible values of n is (a)2 (b) 8 (c) 9 (d) none of these

There are two circles whose equation are x^2+y^2=9 and x^2+y^2-8x-6y+n^2=0,n in Zdot If the two circles have exactly two common tangents, then the number of possible values of n is 2 (b) 8 (c) 9 (d) none of these

Prove that the circles x^(2) + y^(2) -8x -6y +21=0 and x^(2) + y^(2) -2y -15=0 have exactly two common tangents Also find the intersection of those tangents.