Math
posted by helper .
If possible, could a math tutor check the math post question that "daylo3" asked at 6:42 pm today, that I answered?
I don't usually answer posts that I am not 100% sure of the answer.
I would like to know if the way I approached this problem is correct?
Thanks in advance for taking time to do this.

I agree with your approach.
The fact that the two given ratios are different (112/85≠238/175) means that the linear function does not pass through origin.
However, the $7 casts some doubts, since items with C<$17.5 will be sold at a loss. Probably the question was not well designed. It would be more logical to add a dollar or two to the cost to account for ticketing, handling and overhead, instead of subtract a constant amount.
By the way, we appreciate your help and the good quality of answers. 
Thanks so much MathMate!!