Hey can you me posted picture of question

Options B and D are correct

Explanation:
Quadratic formula (shown in attached image) is used to find the solutions to second degree equations.

Let'as check our choices:
Choice A:
5x³ + 2x - 4 = 2x²
5x³ + 2x - 4 - 2x² = 0
This is an equation of third degree. Therefore, this option is incorrect.

Choice B:
x² - 6x - 7 = 2x
x² - 6x - 7 - 2x = 0
x² - 8x - 7 = 0
This is a second degree equation. Therefore, this choice is correct

Choice C:
2x² - 3x + 10 = 2x² + 21
2x² - 3x + 10 - 2x² - 21 = 0
-3x - 11 = 0
This is a first degree equation. Therefore, this choice is incorrect

Choice D:
5x² - 3x + 10 = 2x²
5x² - 3x + 10 - 2x² = 0
3x² - 3x + 10 = 0
This is a second degree equation. Therefore, this choice is correct

Hope this helps :)