Equation of tangent line.

Question

Given two circles, ^{c1=x2+y2-4x-5=0,} c2= x²+y²+6x-2y+6=0, if P(alpha, beta) makes a tangent line equation with both the circles, then what is the tangent line equation?

Answer 1

How does a point (P) "make a tangent line equation"?? 

 

I would like to see the original wording of this problem.