How much longer is a 2 1/2 inch-long piece of string than a 2/5 long piece of string?

If 1/√5+1/√5+1=p+q√r , find the values of p, q and r

For the following geometric sequence, find the recursive formula. {-80, 20, -5, } i need : ')

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?