I am unfortunately not too sure about this, I have not heard of a proportional equation before even after getting my degree, because an equation usually isn't proportional, only expressions are and there are usually 2 terms.
Here's my best attempt. The first equation isn't proportional since y is inversely proportional to the 7 in the denominator. The second is proportional, and the k constant is 10.
I cannot provide any further explanations.
Let me know if this was helpful!