Answer:
15 batteries
Step-by-step explanation:
a. We have
5 batteries = 3 days
5 batteries/3 days = 1
5 batteries/3 days
we need to convert this to 9 days, so
x amount of batteries = 9 days
x batteries / 9 days = 1
5 batteries / 3 days = x batteries / 9 days
b.
5 batteries / 3 days = x batteries / 9 days
multiply both sides by 9 days to get rid of the denominators as well as the days variable
5 batteries * 9 days / 3 days = x batteries
5 batteries * 3 = x batteries
15 batteries = x batteries
x = 15