Answer:

Step-by-step explanation:
So the thing about adding of integers is that is both nos. are positive then you can simply add it and same with negative too.But with negative and positive we should subtract but that is for later.Luckily we have 2 positive integers so we do it like this:
+6 is the same as 6 and +2 is the same as 2 so we...
rule:add the numbers and add the sign.

Slot method
8 optionns n 1st slot
7 options in 2nd slot (since 1 is at 1st slot)
6 options in 3rd slot
5 options in 4th slot
8*7*6*5=1680 ways
Every 5 minutes, you gain 4 gallons. 45/5 = 9, 9x4 equals 36, there would be 36 gallons of water in 45 minutes