Step-by-step explanation:
if there are no typos then only 1) is correct.
3x² + 2x² = 5x²
x + 7x = 8x
2 = 2
2)
8x² - 3x² = 5x²
4x - 3x = x
4 = 4
wrong
3)
x² + 5x² = 6x²
12x - 4x = 8x
2 = 2
wrong
4)
is the same as 3)
so, I am sure the original problem description has something else here. be careful - the original might be another correct answer here.