The answer is X = 12.
This is how to get that answer: the formula for the intersecting secant and tangent outside the circle is a^2 = b(b+c) If you use the numbers in the pic you will get x^2 = 9(9+7) so the number after the equal sign will be 144, so x^2 = 144. To undo the square youre gonna use the square root on both sides, so you have X = 12.
