Number Box Puzzle

Within a 3 x 3 grid there fits the numbers 1 - 9 once. The top line multiplied by two is equal to the second line, and the top line multiplied by three is equal to the third line.

You need to think:

Where would the numbers 5 and 7 fit in? (This is difficult as they are prime numbers).

Also think of the row of the three numbers as one whole number, not three individual numbers.

Good luck, and let me know any answers you come up with!!