factorize completely x^2 2xy Y^2 3x 3y-8?

Answer 1

I'll assume your + key is missing, and you meant
x^2 + 2xy + y^2 + 3x + 3y - 8
(x+y)^2 + 3(x+y) - 8
Hmmm. Suppose z = x+y. Then you have
z^2+3z-8
but that does not factor with rational coefficients, so I suspect a typo. Maybe you can fix it up, and then use my hint to finish it off.