Which coordinate map describes a 90 degree counterclockwise rotation? a. (x, y) --> (x,-y) b. (x, y) --> (y,-x) c. (x, y) --> (-y, x)d. (x, y) --> (-x, y)

Which of the following is the result of expanding

Without any equipment, you can see stars that are 2{,}800{,}0002,800,0002, comma, 800, comma, 000 light-years away. by looking through a small telescope, you can see stars that are 3{,}112{,}000{,}0003,112,000,0003, comma, 112, comma, 000, comma, 000 light-years away. approximately how many times as far can you see using a small telescope as without any equipment?

Asap! i need this done today and i really don’t understand it. some one ! will mark