Answer:
x = 2
Explanation:
The product of the external part times the entire secant of one secant is equal to the external part times the entire secant of the other secant, that is
(x + 4)(x + 5) = (x + 1)(x + 12) ← distribute factors on both sides
x² + 9x + 20 = x² + 13x + 12 ( subtract x² from both sides )
9x + 20 = 13x + 12 ( subtract 13x from both sides )
- 4x + 20 = 12 ( subtract 20 from both sides )
- 4x = - 8 ( divide both sides by - 4 )
x = 2