This is hard to solve when we don't know the visual graph this question is trying to refer from
A 15% percent markup means that the typewriter cost was increased by 15%, or 0.15 by moving the decimal 2 places to the left. If the original price was x, and 15% of it is 0.15*x, we can add them up to get 1.15*x=129.95. Dividing both sides by 1.15, we get x=113 dollars
The answer to an addition problem is called a sum
Hope this helps!
In a line parallel to y-axis, the x would have to be constant, if it's not constant (always the same) then it won't be parallel. Constant values of y could be y=1, y=2... etc, and we have this as an option: y=5, this is the correct answer.
(1) would be parallel to x axis and 2 and 4 are diagonal or sloping lines.
