Simplify:
2x + 3     +      2x – 3 -2
 2x – 3             2x + 3

Answer:

24) D

Let us first solve the first part of the problem

2x + 3 + 2x – 3
2x – 3 2x + 3

(2x + 3)² + (2x – 3)²
(2x – 3) (2x + 3)

(4x² + 6x + 9) + (4x² – 6x + 9)
4x² – 9

8x² + 18
4x² – 9

Let us now solve the second part of the problem

8x² + 18 – 2
4x² – 9 1

8x² + 18 – 8x² – 18
4x² – 9 4x² – 9

8x² + 18 – (8x² – 18)
4x² – 9

8x² + 18 – 8x² + 18
4x² – 9

18 + 18
4x² – 9

36

4x² – 9

Remember that we solved (2x – 3) (2x + 3) = 4x² – 9

So the answer is :

      36

(2x – 3) (2x + 3)