It would take 6

hours or 6.25 hours if John uses the 100 watt pump.
-6-7=-13 because you take -2 and 3 you multiply equals-6 than add -7 and it well give you your answer
This expression is equivalent (9+3)4
6+0=6
When you add any number to 0, that number stays the same since you aren’t adding anything to it. So the answer is 6.