You have to simplify each equation. You can do that by adding similar values to each other:
(the first equation)
8x²y + 7x² - 5y² + 3x - 2 + 2x²y - x² - 2y² + 3x - 4
To make it easier, arrange the values around so that similar ones are beside each other:
8x²y + 2x²y + 7x² - x² - 5y² - 2y² + 3x + 3x - 2 - 4
then add the similar values together:
8x²y + 2x²y = 10x²y
7x² - x² = 6x²
- 5y² - 2y² = -7y²
3x + 3x = 6x
(- 2)+ (- 4) = -6
and if you put them together:
10x²y + 6x² - 7y² + 6x - 6
This isn't the answer to the equation, because it's different. So repeat the process with all the other equations until you find one that is identical to the simplified version.
The answer is the second one: 8x²y + 7x² - 5y² + 3x - 2 + 2x²y - x² - 2y² - 3x - 4
