9514 1404 393
Answer:
x = 6
Step-by-step explanation:
The ratio of the long segment to the whole is the same for both transversals.
(4x +3)/15 = (8+10)/10 = (whole)/(long segment)
2(4x +3) = 3(18) . . . . . . . multiply by 30
8x = 48 . . . . . . . . . . . . . . subtract 6, simplify
x = 6 . . . . . . . . divide by 8