Crap! I factored the 2x^2+9x-10 wrong. You are correct. There is either a typo in the original or the problem is bad. (Or someone made the same mistake I did!)

That doesn't factor into integers if you create a system of equations you end up back where you started, and if you try the quadratic equation you don't get rational numbers.

Thank you for all of your help. I'll ask my teacher tommorow.

Also, something does cancel out. If you factor x² + x - 30 you get (x + 6)(x - 5), and if you factor x² - 36 you get (x + 6)(x - 6). The (x + 6)' s cancel each other other out.