x=13 because you put all of them in an equation and set them equal to 180 bc that is how many degrees are in a triangle so it would be 6x+19+5x-15+3x-6=180 and then you solve the equation so it would be 14x-2=180 then you would add to to both side which would cancel out on the left and make 182 on the right then divide 182 by 14 and you get 13.