Answer:
C
Explanation:
the figure shows a tangent and a secant, then
the square of the measure of the tangent is equal to the product of the secant's external part and the entire secant, that is
(- 5 + x)² = (x - 7)(x - 7 + 5) ← expand left side using FOIL
25 - 10x + x² = (x - 7)(x - 2) ← expand using FOIL
x² - 10x + 25 = x² - 9x + 14 ( subtract x² from both sides )
- 10x + 25 = - 9x + 14 ( add 9x to both sides )
- x + 25 = 14 ( subtract 25 from both sides )
- x = - 11 ( multiply both sides by - 1 )
x = 11