Answer:
x = 14.4
Explanation:
This is similar triangles where the large one is proportional to the smaller triangle inscribed inside it. Lay the 2 triangles out like so and the 30(hypotenuse) is proportional to 18. You can use the scale factor to find the "x" by doing: 24/1.66666666667(which is the scale factor you get from 30/18). This should give you 14.4.