I doubt that this is in the Sec 3 A Maths syllabus for standard schools, so you can skip this question, unless you are taking the IP syllabus or you are motivated to do beyond what the Sec 3 A Maths syllabus offers.

The key idea here is to pay attention to the structure of the function.

In part (i), the main body of the fraction is the fraction 1 / ("something" + 5). This indicates that the outer function is g(x). The "something" is x² - 1, and this indicates that the inner function is h(x). So, a good function to model this is gh(x), but not the other way round.

In part (ii), the main structure is the 2 and the 1, so k(x) is the outer function. Upon closer inspection, the x can be replaced by 1 / (x + 5), so this indicated that g(x) is the inner function. So, we have kg(x) to model this.