Answer:
x = 18.8 
Explanation:
(6x + 19) is in linear pair vertically so, 
it's value will be 180 - 6x + 19. ......( angles in linear pair are supplementary) 
now, 180 - 6x + 19 is corresponding with (4x + 11)
therefore, 4x + 11 = 180 - 6x + 19
 4x + 6x = 180 + 19 - 11
 10 x. = 180 + 8
 10 x. = 188
 x = 188/10
 x. = 18.8
Cross - check:-
4x + 11 = 180 - 6x + 19
4 * 18.8 + 11 = 180 - ( 6 * 18.8 +19)
86.2. = 86.2
therefore, x = 18.8 is the correct answer