8 - 15 means subtract the positive number 15 from 8.
8 - 15 = 8 + (-15) = -7
8 - (-15) means subtract the negative number -15 from 8.
Subtracting a negative number is the same as adding a positive number.
8 - (-15) = 8 + 15 = 23
8 - 15 = -7, and 8 - (-15) = 23. The expressions mean different operations and have different answers.
That means 8% of his trading cards are not in a binder. How we find this out is subtract 92% from 100%, and the remainder is how many he does not have in a binder, for whatever reason.
Number 4 is a, and 6 is d, but I'm not sure about 5
Divide 50 milliliters by 1.25 milliliters to get the total number of days.
50/1.25 = 40
The medicine will last Doug 40 days until it runs out.