If x and y have to be equal as solutions to this equation,
then for whatever value of x (but x cannot be zero),
c = 8/x - 2
In other words if x and y are equal to 1 then c is equal to 6,
if x and y are equal to 2 then c is equal to 2,
if x and y are equal to 4 then c is equal to 0
etc.