As long as your indexes are the same (which they are; they are all square roots) and you radicands are the same (which they are; they are all 11), then you can add or subtract. The rules for adding and subtracting radicals are more picky than multiplying or dividing. Just like adding fractions or combining like terms. Since all the square roots are the same we only have to worry about the numbers outside. In fact, it may help to factor out the sqrt 11:

. The numbers subtract to give you -9. Therefore, the simplification is
Answer:
Gas left after 5 hours is: 10 gallons
Gas left after t hours is : sorry I don't know
Step-by-step explanation:
Subtract 2 everytime you count an hour
Hope this helps
Answer:
A
Step-by-step explanation:
See paper for order of operations
Answer:
closed System
Step-by-step explanation:
Metal is a conductor of heat, coolness, and electricity. In terms of electricity, only closed circuits will work because electricity flows in a closed loop. If the can is being cooled successfully, then the heat is flowing out of the can into the fridge while cool air from the fridge is flowing into the can forming a loop. So the answer is a closed system.