Answer
$x = 22.5$
Work Step by Step
If three parallel lines cut through two transversals, then the segments on one transversal that was cut by the parallel lines are proportional to the segments on the other transversal that was cut by the parallel lines.
Now we can set the proportions to compare the segments on one transversal to the segments on the other transversal:
$\frac{x}{9} = \frac{20}{8}$
Use the cross product property to get rid of the fractions:
$8x = 180$
Divide both sides by $8$ to solve for $x$:
$x = 22.5$
