Answer:
x = 2
Explanation:
Given 2 secants intersecting a circle from an external point, then
The product of the external part and the entire part of one secant is equal to the product of the external part and the entire part of the other secant, that is
(x + 1)(x + 1 + 11) = (x + 4)(x + 4 + 1)
(x + 1)(x + 12) = (x + 4)(x + 5) ← expand both sides
x² + 13x + 12 = x² + 9x + 20
Subtract x² + 9x from both sides
4x + 12 = 20 ( subtract 12 from both sides )
4x = 8 ( divide both sides by 4 )
x = 2