9514 1404 393
Answer:
x = 19
Explanation:
The marked (consecutive interior) angles will be supplementary when the lines are parallel.
(3x +10)° +(5x +18)° = 180°
8x = 152 . . . . . . . . . . . . . . . divide by °, subtract 28
x = 19 . . . . . . . . . . . divide by 8