Answer:
PD = 30
Explanation:
2 secants intersect inside a circle the product of their parts are equal, that is
20(2x + 3) = 18(2x + 6) ← distribute both sides
40x + 60 = 36x + 108 ( subtract 36x from both sides )
4x + 60 = 108 ( subtract 60 from both sides )
4x = 48 ( divide both sides by 4 )
x = 12
Hence
PD = 2x + 6 = (2 × 12 ) + 6 = 24 + 6 = 30