which expression has a value of 6 when x=2 and y=4?

Let's verify all the options to the question. Clue given: x = 2, y = 4
Option A:
(x² + 8) ÷ y - 2
=> (2² + 8) ÷ 4 - 2
=> (4 + 8) ÷ 4 - 2
=> 12 ÷ 4 - 2
=> 3 - 2
=> 1 ≠ 6
This answer does not equal 6.
Option B:
(x² + 8) ÷ (y - 2)
=> (2² + 8) ÷ (4 - 2)
=> (4 + 8) ÷ (4 - 2)
=> 12 ÷ 2
=> 6 = 6
This answer is correct as 6 = 6.
Option C:
x² + 8 ÷ (y - 2)
=> 2² + 8 ÷ (4 - 2)
=> 4 + 8 ÷ 2
=> 4 + 4
=> 8 ≠ 6
This answer does not equal 6.
Option D:
x² + 8 ÷ y - 2
=> 4 + 8 ÷ 4 - 2
=> 4 + 2 - 2
=> 4 ≠ 6
This answer does not equal 6.
So, after verifying all our options, we can conclude that Option B is correct. Therefore, Option B is the correct answer.