Substitution is a good idea. You will get , from which you can use the quadratic formula:
If this equation is to have any real roots at all,
Then you have
and you can use the quadratic formula again.
This is a homework. Not quite an urgent one - I need it for monday and I have had it since monday. Unfortunately, few ideas occured to me.
Obviously, a reasonable step, perhaps, is to make a substitution, but then, I believe, we get only a link between m and y, assuming y is the substitution y = x*x -2x + 2, and no link between m and x.
The problem is taken from a university entrance test. We need this equation to have 4 different roots.