What is the difference?

Answer:
[9x² - 2x + 8]/2x(x - 2).
Explanation:
We should common the denominator by multiplying the denominators of the two terms (2x)(x - 2) and dividing each denominator by the common denominator.
[2x(5x) - (x + 4)(x - 2)]/2x(x - 2)
= [10x² - (x² + 2x - 8)]/2x(x - 2)
= [10x² - x² - 2x + 8]/2x(x - 2)
= [9x² - 2x + 8]/2x(x - 2).