One possible answer is:
Un = (3n3 - 3n2 + 78n - 8)/560 for n = 1, 2, 3, 4.
Four fifths.
Yes, fifths arer bigger chunks than sevenths.
Four fifths is the larger fraction.
negative one and two fifths
No.
3 sevenths
It is four fifths
6/70
twenty eghiths
You multiply....
519/20
No