Turn all of the below to standard form:
4x10^9
2x10^-5
3.7x10^6
3x10^8

4000000000
0.00002
3700000
300000000

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.