If the circles `x^2+y^2+2ax+c=0 and x^2+y^2+2by+c=0` touch each other, then find the relation between `a, b and c`.

If the circles x^2+y^2=9 and x^2+y^2+8y+c=0 touch each other, then c is equal to:

The two circles x^2+y^2=ax and x^2+y^2=c^2 (cgt0) touch each other if

If the circles x^2 + y^2 + 2ax + b = 0 and x^2+ y^2+ 2cx + b = 0 touch each other (a!=c)

The two circles : x^2+y^2 =ax and x^2+y^2=c^2 (c > 0) touch each other if :

If the circles x^2+y^2+2ax+c=0 and x^2+y^2+2by+c=0 touch each other , prove that c is always positive .

If the circles x^(2)+y^(2)+2ax+b=0 and x^(2)+y^(2)+2cx+b=0 touch each other (a!=c)

If the circles x^(2)+y^(2)=9 and x^(2)+y^(2)+8y+C=0 touch each other,then c is equal to

If the circles x ^2 + y ^2 + 2ax + c = 0 and x ^2 + y ^2 +2by + c = 0 touch each other, prove that 1/a ^2 + 1 b ^2 = 1/c

If two circles x^(2) + y^(2) - 2ax + c = =0 and x^(2) + y^(2) - 2by + c = 0 touch each other , then c =