To set this up you will set the two angles equal to 180° since it is a straight line This will make the equation x+6x+19=180 Combine like terms. 7x+19=180. Subtract 19 from both sides. This will make it 7x=161 Divide both sides by 7. That will make it x=23 Next plug in the x to solve for abc. 7(23)+19. This equals 157