Answer:
2
Explanation:
The rule for secants from an external point is that the product of the near and far distance to the intersection with the circle is a constant.
EA·EB = EC·ED
(x+12)·(x+1) = (x+4)·(x+5)
x^2 +13x +12 = x^2 +9x +20 . . . . . . eliminate parentheses
4x = 8 . . . . . . . . . . . . subtract x^2+9x+12 from both sides
x = 2 . . . . . . . . . . . . . divide by 4
The value of x is 2.