Answer:
7/20
Step-by-step explanation:
GIven:
Battery A = 4/5 remaining
Battery B = 9/20 remaining
assuming both batteries are otherwise identical (except for charge level remaining), then,
Battery A - Battery B
= 4/5 - 9/20
we need to convert both fractions to same denominator to perform the subtraction easily. Note that the Least Common Multiple for 5 and 20 is 20, hence we convert both denominators to 20,
Battery A - Battery B
= 4/5 - 9/20
= (4/5) (4/4) - 9/20
= 16/20-9/20
= 7/20