SOLUTION: The symbol $ is defined by: a$b = a^2-4b^2 if x $y =3(y$x), express y in terms of x.

Involved in that equation are , , and .
We find those by substituting in 







So the given equation



becomes



We solve that for y in terms of x:








 




That's the solution, but you may rationalize the denominator if you like:







Edwin