Including variables in math text answers

I am wanting to have the students answer with the equation “y=3x” and proportional equations such as this. I am not wanting to use tables, as my students can respond 3x, but are struggling with writing the equation on their own. Is there a way to have the students input a proportional equation and have it graded by Desmos?

Are they entering any proportional equation, or a specific one?
For a specific one:


#the specific values don't really matter below
check= targetEq.evaluateAt(2,1) = studentEq.evaluateAt(2,1)  and  targetEq.evaluateAt(3,2) = studentEq.evaluateAt(3,2)

You could also use pattern matching to just check for the right form.