1. 2x² - 3x - 7 = 0
2. I think there is something wrong with the equation in number 2. There has to be a degree 2 in the equation. If there's not, then it is considered as a linear equation, not as a quadratic. I hope you can follow this up.
3. x² + 7x + 12 = 0
4. 2x² + 5x - 7 = 0
5. 2x² - 6x - 15 = 0
6. x² + 3x + 49 = 0
7. x² + 16 + 8 = 0
8. x² + x + 2 = 0
9. 3x² = 0
10. x² + 8x + 9 = 0