The option A is the right answer
think of it as one group of adult tickets and 3 groups of student tickets which is 4 groups, so divide 536 by 4. the answer is 134 which is the amount of adult tickets sold (if you wanted the amount of student tickets then you can just subtract 134 from 536).
I always used rise over run. which is when you count up the y axis for run and count over on the x axis for the run. then take your rise over run and there is your slope.
