Answer:
as per my point to view you can use a L.C.M so you can get the answer or you can try using a exponent way like 5by 1 as n value is 1 so it may give yoh answer
B) (16 + 20)a - 18b
16a and 20a are both positive and 18b is the only negative it’s easier to add the positive with each other then the negative and a positive then add other positive
It’s not my answer but I think it’s correct!
The answer is 4/12
That easy