Answer:
2.
4x^2 + 4 - 5x + x - 2x^2 + 8
= (4x^2 - 2x^2) + (x - 5x) + (4 + 8)
= 2x^2 - 4x + 12
=> D is correct
3.
2x^2 + 6x - 7x + 8 - 3x^2 + 1
= (2x^2 - 3x^2) + (6x - 7x) + (1 + 8)
= -x^2 - x + 9
=> C is correct
4.
B is correct (4 and 3)
Hope this helps!
:)
