Are you sure you wrote it right because it should be -42.99
Show me a picture of the equation
to make the proportion we make the ratio of the similar sides
For example
4/8 = 12/x
or we can write it as 4/12 = 8/x
or 12/x = 4/8
So last option is correct
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