Answer:
2(a) 2n + 14
2(b)

Explanation:
For (a), all you have to do is interpret the question itself and turn it into a mathematical operation.
Firstly, as the question has given, the number in (a) should be n.
Therefore, twice of n is 2n, and the sum of 2n and 14 is 2n + 14.
Same goes for (b). The question says a number multiplied by x, meaning nx, and nx halved, getting
.
Hope this helped!