Find the simplified form of the expression. give your answer in scientific notation.
(4x10^10)(9x10^-5)

(4x10^10)*(9x10^-5) =
36 * 10^5 =
3.6 x 10^6

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.