What does the double bracket mean in this equation: f(x)=[[x]]

Me! i really need to get this right before 9. prove the divisibility of 7^6+7^5-7^4 by 11. use factoring so you get a number times 11. just tell me the number. i need this done asap

Atorch and a battery cost 2.50 altogether. the torch costs 1.50 more than the battery. what fraction of the total price is the torch? give your answer in its simplest form.

Atransformation t : (x, y) (x-5,y +3) the image of a(2,-1) is