How much does it cost to buy 53 fraction calculators? how much to buy 27 scientific calculators? how much to buy 9 graphing calculators.

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.

C+19÷-17=17c+(-1.11764706)=17c=.11764706)c=18.1176471

1) 11, because it's a perfect square.2) 4√3