Girl balances books, recites 100 digits of Pi and solves Rubik’s cube (video)

play, you enjoy mathematics. then solve:

A circle represented by the equation (x^2)+(y^2)=25 is on an ordinary real x-y axis.

Two lines, tangent to the circle, the first being tangent at (-3,4) and the second at (4,3) intersect at point (a,b). Find the point (a,b).