What is the difference for this question?

For this case we have the following polynomials:
 (5x2 + 2x + 11) - (7 + 4x - 2x2)
 Rewriting we have:
 5x2 + 2x + 11 - 7 - 4x + 2x2
 By grouping terms of the same degree we have:
 x2 (5 + 2) + x (2-4) + (11-7)
 Rewriting:
 7x2 - 2x + 4
  the difference is
 7x2 - 2x + 4

B. 25%

Step-by-step explanation:

To do this you divide.

1.2 / 1.6 = 0.75

1.00 - 0.75 = 0.25

0.25 = 25%